Unable to use T-Mobile Home Internet with work VPN, any suggestions?

Been using TM 5g home internet for work for the past few months. Logged out last Friday without any issues to speak of. On Monday morning, my services were inop. My work computer showed connected, as did the TM app. After a few days of speaking with my companies IT dept, they informed me the issue is with my ISP. I called TM tech support to see if they had any information to provide. The tech i spoke with was super nice and sounded knowledgeable. He said as of Monday they'd started receiving an influx of calls with this exact issue. He said they are working on a solution, but could not provide a timeline. In the meantime, I'm completely unable to work. If TM cannot get this fiugred out in the next 48 hours, I'll be forced to switch providers.

All of this is really unfortunate because I've been a champion of TM 5G. I now look like a donkey to the folks I've been telling all these great things. Fingers crossed they come through.

@jsteele-az my issue started as soon as I switched ISP to T-Mobile. I have noticed there are still some little quirks when connected to my company VPN. Sometimes I have to log off the internet then re-establish the connection for it to work. So far it's still working good. The T-Mobile rep said if your distance isn't too far that you could also try the 5 GHz network but range is limited, so the closer the better.

AJ1234 wrote:

[...] Worked out my VPN issues and my security cameras are working now.  

@AJ1234 My wife and I use company VPNs and they seemed to stop working the weekend of Jan 20, 2024. Is that when you started having problems?

My Ring cameras seemed to have stopped communicating with the mother ship, but Alexa appears to be up and running. I was already using the 2.4GHz band, but I didn't check the WPA settings. I'll try again next time I'm up there.

I'm in a rural area (Pine, AZ) and their aren't many options, so fixing this is critical for us to WFH. My VPN connected fine (more-or-less) to company resources, but I couldn't get to Google Drive. My wife's VPN had troubles using Teams and couldn't connect to a cloud app (website) she relies on.

Frustrating. 100% agree with @Homerthefox that it’s deceptive to market this as broadband alternative when so many people rely on WFH.

My company uses Cisco AnyConnect VPN. I've been having all the same issues mentioned in this thread and gone down the IT rabbit hole trying to remedy this issue. Finally found a knowledgeable T-Mobile technician that explained if personal or work VPN or systems are operating on IPv4 then you need to go into your T-Mobile home internet app > select network > click "+" to add network > name network > create password > select 2.4 GHz band > select WPA/WPA2 > WPA "TKIP & AES" > then save the new network and connect. Worked out my VPN issues and my security cameras are working now.  

I can't believe T-Mobile support just flat out told me that their internet service is incompatible with a VPN! How can they advertise that I can use this for work at home with multiple high speed streams, but just conveniently neglect to let me know I can't use a VPN! No suggestions for solutions, he just offered to cancel my service immediately!

Try tailscale as your VPN.   I have a TM Nokia modem in from of a linksys EA8300 router running openwrt which is running tailscale.   Openwrt takes a little learning curve but tailscale is dead easy to create your own VPN without any monthly fee.   The t - mobile  model does not have an IPV4 address and with tailscale subnet routing your don't need one to browse your home network or remotely view your cameras. 

https://openwrt.org/docs/guide-user/services/vpn/tailscale/start

Works like a champ.

No doubt T-Mobile reads these threads and fixed it so that you can't use VPN. I too was taken a back by this inability to access VPN, rendering working from home - something that 80  percent of the work force is doing these days shocking.  Ill give you in non technical terms what was explained to me..as to why they don't allow it...the towers can't handle that amount of traffic or data moving through the air ..or some garbage along those lines.  I live in a rural area. The closest tower is less the two miles away and the signal to my house sucks. The plan offered to me originally for switching was then retracted and I was told that plan isn't offered in my area. So the cost for service doubled and the data speed became limited.  And then to find out no VPN?  Not a happy camper. I've been a t mobile cell phone user for 12 years and stuck with them while they got their together. Customer service has always been very good. But this experience of being misled and misinformed  has really soured me.  Great concept - but poor execution and would not recommend their home Internet.   

This is insanely frustrating. I can't do half my job unless I sit in a cafe with broadband access or work from a friend's house. But the part that is infuriating is every time I call T-Mobile, I get different answers from different people. Call 1: "Can't do anything for ya. Sorry." Call 2: "We can get you to a higher tier of support who will be able to help if you can get us your VPN Settings from your IT Department." Call 3: "None of what call 2 is true. Sorry to say it, but they lied to you. There is no higher tier of support."

I bet if I called a 4th time, I'd get another completely different answer. I had this totally fixed by changing the MTU size on my router and now, even changing it directly on my laptop makes NO difference. There really needs to be a fix for this. If I had access to any other ISP that wasn't worse than this, I'd drop this service instantly. Unfortunately, I'm stuck since I live in a rural area. I'll stop complaining now. 

Wanted to post an update. Unfortunately, earlier today, my VPN issues returned. I have no idea what happened. I have tried everything I can think of and have even lowered my MTU size to the lowest setting and am still not able to connect to most apps while on my VPN. I apologize if you try my solution and it doesn't work for you. Was working perfectly at 1450 MTU until midday today. Hoping it's just an intermittent thing, but still wanted to post here. 

Hola Everyone, 

This is something I posted in another T-Mobile forum a while back. After putting some research into this, I believe I have found a solution (at least one that worked for me).

PLEASE NOTE: PART OF MY SOLUTION IS USING MY OWN WIRELESS ROUTER ATTACHED VIA ETHERNET CABLE TO THE BACK OF MY HOTSPOT MODEM. THE INSTRUCTIONS I LEFT BELOW WILL NOT BE OF MUCH USE TO YOU IF YOU ARE NOT USING A WIRELESS ROUTER.

This does not require much tech-savviness as I found what I needed from a YouTube video and a little googling on how to access the settings I needed, which I'll post a link to at the end of this. Basically, it's the MTU (Maximum Transmission Unit) settings that T-Mobile uses. You don't really have to know much about this other than how to find out how to change it, either on your computer or on your wireless router (if using a wireless connection). 

Most internet providers set their MTU size at 1500. This is more-or-less a standard most in the industry follow. From what I found, T-Mobile sets their MTU size at 1450. I'm not going to go into explanation on how this works; just know this is the problem. This tiny difference seems inconsequential, but can make or break your VPN connection. Unfortunately, it's on us as the customers to find our own solution(s) to this problem. 

This YouTube link gave me the information on how to check my MTU settings and change them on a Windows PC. This is a solution specifically for if you want to only change the MTU Size on individual PC's in your home. Ultimately, I did not change my MTU Size on my laptop, but the part of the video that helped me find the MTU Size was key to figuring this whole thing out. The link will take you directly a few seconds right before the spot you need to pay attention at begins:

 

I'm not a Mac user and am not experienced with using them, but this is a link for all y'all Apple fanatics that I found while I was searching for a reason for this problem. It was the first article I came across that set me on the path to figuring out how to change my MTU setting. Hope it helps:

https://amithkumarg.medium.com/resolved-t-mobile-home-internet-vpn-issue-2f5ca594c23e

And, lastly, I use a TP-Link Wireless router. This link is for TP-Link device owners and shows you how to change the MTU Size. There's no way I can find links to all the different types out there. However every brand's settings are easily searched on Google, so good hunting to you and good luck: 

https://www.tp-link.com/us/support/faq/1134/

I hope this helps some people. My issue is (self)resolved.