For about the last month, my phone has been extremely slow connecting to data when leaving my Wi-Fi zone. Usually it only takes a few seconds when I get out of range of my Wi-Fi (or purposefully turn off my Wi-Fi) to connect to data. But it has been taking between 1 to 5 minutes consistently to connect to data this past month.
If I restart my phone, it will automatically connect straight to data once the phone turns on. But it doesn't fix the issue. The next time I connect to Wi-Fi and then disconnect, it will take a long time to find the data connection again.
I've tried manually turning off Wi-Fi before leaving my house and sometimes it connects faster, but not always.
Also this is all around where I live, in an area where I've always had excellent data speed.
There's no sign on the top bar of my phone that it's even trying to connect like the LTE symbol with the arrows. It's just empty space next to the bars for minutes until it decides to connect and then the data symbol shows up next to the bars.
I have a Samsung s8 and my brother is having the same issue and he has a Samsung s20. I'm assuming this is more a t-mobile issue than a Samsung issue though?