Intermittent Incoming Calls Going Straight to Voicemail with No Ring

I'm having this issue as well.  I've done all the steps, swapped my device, installed a new sim, and even standing in the store had the associate try to call me and no call came through.  I am absolutely fed up with the issue and lack of resolution. I've been a sprint customer for years and never had this type of problem.

This isn't a device or location related issue as it persisted across the whole state of Texas during a business trip.  Figure this out T-mobile, its ridiculous that for 2 months now you've wanted payment (that I paid on time, everytime) for a service that does not work.

This might not work for everyone, but what worked for me was turning off Wi-Fi Calling (Settings > Network & Internet > SIMs > T-Mobile > Wi-Fi calling off). I have a Google Pixel 6a, and people were complaining that they had to call me 2 or 3 times before my phone would actually ring. The first 2 calls would go straight to voicemail, and I did not receive a missed call notification on my phone. Somehow I think that the phone just misses the call as it's trying to decide whether to route the call over WiFi or the T-Mobile network.

Having same issue. Was told by friends to dump T-Mobile. Once dumped, no issue with other carriers.

Same problem here too. 

I am having the same issue for all my phones for over a month it seems, incoming calls thru whatsapp work, but regular phone calls work inrtermittently, mostly does not work! Yet to find a solution for the issue, may be forced to change carrier if issue continues.
 

People are telling me that when they call me that the call is going directly to voicemail. This does not happen all the time. But at times it will ring one time and then go directly to voicemail without showing up on caller ID or notify me that it was a call. I use this phone for business. I can't have this? What's going on with T-Mobile is there a solution?

I’m using a iphone11

I've just fixed my problem of calls going straight to voicemail. After trying all the usual suggestions, I looked at the "call settings" screen then tapped the "call forwarding" title and the phone went thru a settings update motion. Then went it stopped it showed the phone number that the calls were going to and they where off by one number. The last digit was not my voicemail number and I don't know how that got changed. But I do know that T-Mobile has done us a huge miss justice by leaking our personal data to the web and that may have had something to do with it. I'm leaving this provider. 

It doesn't seem to be an issue with the carrier or phone. I had this problem from time to time with my previous two carriers. I think it has more to do with towers/reception than the phone or carrier.

So I am using oneplus phone and encountered same question recently(I cannot received any phone calls and they all went to voicemail without ring).

Here are steps I tried:

1. I called 611 and a representive told me to try deleting all the unimportant voicemail. After I deleted all my voicemail,  the problem disappered, but after a few hours, it showed up again.
2. I followed the official instruction and dial ##004# to reset some settings(##21# does not worked for me), and followed solution in this post, dial **61*18056377243**30# to set ring time to 30s(someone mentioned ##40# but that does not worked for me as well).
3. At last I updated my Coloros system and found out that signal icon changed to 5G and there is an HD icon as well, then everything works well for me. 

Personally I think this problem is related to 5G, volte, Android/OS version and voicemail. I think update the system solved the problem but not sure whether step 1 and 2 played some role in solving this problem. So I wrote these steps down and hope it will be helpful for someone.

I found a solution to the straight to voicemail problem.

Delete T-mobile visual voicemail.

Not surprised that the problem originated with t-mobile, not the phone.