WIFI Calling Preferences Being Forced to Cellular Preferred

I have the same issue as reported by many other users: on Samsung A32 5G (SM-A326U) the WiFi calling preference is constantly being reset from WiFi-preferred to cellular preferred.

T-MOBILE needs to work with Samsung to address the issue!

I continue to have the "Wi F calling preferences updated to optimize network experience" message appear on my Galaxy S9 constantly. It is changed from Wi-Fi to cellular, even though I have only one bar on cellular service and am 5 feet away from my ASUS RT-AC86U router. It seems like I miss calls when it is reset to cellular preferred.

I have many issues with this unwanted "service". If I set a preference, it is what I want and I expect my preference to be honored. Is this reset only on my phone, or is it also recognized by T-Mobile so if I get a call T-Mobile will only use cellular and not work if I don't have sufficient coverage?

T-Mobile has replaced my SIM card, but that didn;t help. There was a suggestion to clear the cache partition and reset network connection. I have done this repeatedly and it doesn't work.

It looks like I have three solutions: Take my Galaxy S9 to AT&T, stay with T-Mobile and replace my Samsung with a different manufacturer’s cell phone, or go to Spectrum/Verizon and get a new phone.

Note to T-Mobile: If you are monitoring this issue, please respond.

IT looks like this has been fixed.  The latest update for My S21 leaves WiFi preferred, locked in. 

Can't believe I have to switch to verizon because of this

Bottom line primary trigger causing "Cellular Preferred" changes is limited consistent Wi-Fi internet data throughput or bandwidth, this by absolutely no means is wifi signal strength at the router but combination of all specifically between the modem itself and the wifi calling app itself on your device, home modem internet signals are rarely consistent although your wifi might be bad ass at hiding it for other types of devices; this can all drastically be affected also by excessive Google/games/apps limiting bandwidth to wifi calling app also multiplying the issue also having wifi scanning built into everything.  Wifi scanning basically momentarily pauses or severely limits your current wifi connection while the radio adjusts between wifi channels trying to locate other networks to meter yours against, causing the wifi calling app to disconnect unexpectedly and flip to cellular. 

Bottom line primary trigger causing "Cellular Preferred" changes is limited consistent Wi-Fi internet data throughput or bandwidth, this by absolutely no means is wifi signal strength at the router but combination of all specifically between the modem itself and the wifi calling app itself on your device, home modem internet signals are rarely consistent although your wifi might be bad ass at hiding it for other types of devices; this can all drastically be affected also by excessive Google/games/apps limiting bandwidth to wifi calling app also multiplying the issue also having wifi scanning built into everything.  Wifi scanning basically momentarily pauses or severely limits your current wifi connection while the radio adjusts between wifi channels trying to locate other networks to meter yours against, causing the wifi calling app to disconnect unexpectedly and flip to cellular. This in turn blows for us all because it is implemented into almost all newly developed/updated apps to be allowed in the Google Play Store, even the built in Android app that senses input from a simple touch of your touch screen and keyboard apps cause wifi scanning to momentarily take place, had mine changing it seemed 50% of the time swiping my screen to unlock. The standard Android settings menu allows you turn off wifi scanning so they make it seem but this toggle only disables wifi scanning features at user level installed apps, not wifi and GPS scanning for system based ones provided by Android/vendor/Google.

Getting an E911 address set in the first place is the first essential part for Voice over LTE, video calling, and WiFi calling features to become active and usable at all in the first place, otherwise yours was functionally disabled without it, even though the toggle is there, with no E911 it causes IMS registration to fail, dis-allowing these functions entirely from the cell tower on device bootup. Testing with Airplane mode on then wifi, calls will drop regardless if E911 address is not in place, IMS Registration status is verified in SIM card status will tell you if Voice over LTE, video calling, and WiFi calling features are active and functioning Now that you have it, it WILL be a matter of time until you find this setting changing to cellular preferred constantly occurring throughout use as most ALL other carriers included Android 9+ Google software bundled phones go. Tracing through logs in App Ops I have identified this change over issue down to a combination of all softwares, implemented first by Google through most any Play Store apps eventually brought into standard Android OS development and also infused into vendor/carrier installed apps just the same is the ongoingly largest battery draining issue - randomly occurring wifi scanning also mixed in with Geo Location/NFC triggers which are all binded directly with GPS Location Services function. Bottom line primary trigger causing "Cellular Preferred" changes is limited consistent Wi-Fi internet data throughput or bandwidth, this by absolutely no means is wifi signal strength at the router but combination of all specifically between the modem itself and the wifi calling app itself on your device, home modem internet signals are rarely consistent although your wifi might be bad ass at hiding it for other types of devices; this can all drastically be affected also by excessive Google/games/apps limiting bandwidth to wifi calling app also multiplying the issue also having wifi scanning built into everything. 

The only select few apps I set to allow location access to is Google Maps cloned along with google play services, isolated in my cloned Island work profile for when needed , then two I set to "allow only while using the app which are both needed for IMS registration to successfully complete at boot: DiagMonAgent and IMS Service. Since IMS registration takes place only once on devices at bootup, if I have wifi left on before rebooting it may trip to Cellular Preferred only once just at this moment depending how fast wifi connects vs completion of IMS registation. So as long as I don't restart with wifi on my issue is now 100% resolved and now completely entirely non-existent, "WiFi Preferred" calling mode is now holding persistently, only now accurately displaying unavailable currently when wifi diminishes before dropping or as changing WiFi to another connection, IMS re-establishes and maintains "WiFi Preferred" option through every transition. The other guy can above can run back to Verizon if so he chooses but either way we ALL live in this Google/Microsoft driven world whom both want to know every last detail of none other than you, good luck getting them to change their ways or to get your new carrier to sell you a device that has neither but works on their network, otherwise mod your own device you personally own how you like the way, we in the free/open-source Linux community, always have. Windows 95 does still function also if you so choose to use it for something or like demonstrating how things USED to work in days of ol, but if you want to use it with today's world of software and hardware both, you won't have much luck.  If you merely buy a device from any standard Cell Phone Carrier you are in fact buying into their whole entire knowledgeably ignorant scheme to hand them hundreds of dollars only because their service is somehow unexplainably "better" than their identical competition with identical devices and consolidated shared Cell towers, sales are not developers are not technicians, continue the endless loop. Open source already fixed the problem, Google and Microsoft never will because it is 100% strictly marketing based and profiting them, if a product doesn't work well or no longer does after being updated to "latest improved software" you'll come shovel out hundreds for another new one to replace a 6 month old new one….right??? There are other forums for those carriers too once you find yourself in the exact same current situation once your new device updates itself. Also good preventative to avoid vendor forced OS updates that some have found their devices booting up to regardless of disabling automatic system updates (vendor/carriers do have the ability to and do force system updates occasionally in waves to all devices reporting not being updated after a set time duration expires pushed through SMS/GMS code in the System Update app) if using Island then freeze (disabled until YOU open it)the update app and only update once you know updates are stable, most vendors wait months after security updates are released before they push them to available for your device to see in the first place so a little extra time on your end to actually verify stability between other actual users will keep this and any other unexpected downgraded updates from disrupting life

Welcome to customer support and sales experience. Thats precisely why I am a technician now, I see no point in ignorantly lying aimlessly to people just to make more sales. Pretty disgracing of a customer service team though altogether, never in my life, let alone on multiple recent hour plus long calls to these "let play stupid and clueless" antic assholes, if you have noise cancellation off on your sound you can here the agent and the group of thieves surrounding them in a hopeless lonely cubicle literally laughing along while saying they have never heard of this in all their years in prepaid/postpaid support, it has to be your phone, come into our store and we'll explain it all for you with a new $1800, all glass cased device with new 5G technology which is slower and less storage capacity than your outdated IP68 military grade rating that runs smoother and faster than new, only functioning thing accounting for this $1400 price difference is an updated over-rated high mega-pixel camera that actually takes the same 1080p picture edited with software rendering, also of which comes standard on $100 price range models today

Thanks for jumping in with this….but, unfortunately this doesn't solve the problem. I've had all my phones properly set up with e911 and still have the same problem. I certainly wish it was that simple!

Today I was on the phone with tech support for over two hours. I was not impressed with their level of knowledge (on anything!). Surprisingly (or maybe not) the first level support person I spoke with had never heard of this problem (it didn't help that she was so heavily accented I couldn't understand her half the time …..why do they use those folks for tech support???). I assured her that it was all over the internet. Ultimately I explained in detail the situation and she consulted other support folks and came up with a workaround. Not a great one certainly, but something that should help….at least at my house. The workaround? A cell phone signal booster. They've agreed to send me one (a loaner w' a $25 deposit). In theory, this will amplify the 4G LTE signal enough that, if, by chance, my phone randomly switches from WiFi preferred to Cellular preferred at least the cellular signal will be strong enough that I can still send and receive calls/texts. This does not change the annoying fact that the phone won't stay on WiFi preferred. Annoying also because, not only am I unable to get texts or make calls when it swaps, but if it does swap to cellular and still works, I unknowingly use cellular data rather than Wifi data so it can end up costing more. And I will still have the issue at my vacation home where the problem is far worse (they'll only give me one of these boosters!). At this date there is no proposed fix for the random swapping to cellular preferred….unless you use "DazedandConfused" method which I'm not quite up to tackling at this point (his method would likely leave me dazed and confused!). They did suggest to turn on airplane mode and then turn WiFi on…..this would keep it from going to cellular….but, as I pointed out to them, then if you wonder away from your wifi (you might forget) you get absolutely nothing. That's even worse! Apparently all android phones...especially Samsung ...have been plagued by this after an update about 6 months ago. In hindsight, this would have been the time to swap to an iPhone. Certainly the android folks will come up with a real fix….right???   Although I guess I can't really blame T-Mobile for all of this, I'm still very disappointed in their tech support…..they should have had this all figured out with all possible workarounds….it shouldn't take two hours!