T-Mobile and Hot spot, NOT

- Member Since: May 30, 2018
I am starting this discussion out of frustration with dealing with terrible-Mobile. Hopefully, someone has solved the problem since t-mobile technical cannot!!
I have a Huawei Honor 6 (android) with current OS. My T-Mobile plan (literally) is 5GB data and 30min of talk time each month. Over the last year or so, I have made several attempts to have my phone serve as a hotspot for my computer when the local wireless internet is down/slow, My phone and computer connect (both 'see' each other), however, the phone does not get through to T-mobile network for computer-initiated data. Incidentally, the phone's data needs are met adequately--no problems there at all. All apps work just fine. IT's only the computer connection that has not network access/.
Curiously, I was just in the Bahamas. I had a sim card for their network (BTC) and funds in my data-only account. For three months, my phone worked great as a hotspot. When I returned to the US and went back to terrible-mobile, no data again. as before, the phone and computer connect. On the computer, the node is marked as 'no internet.' On the phone, I can see the computer, both with IP4 and MAC address. Signal strength is 5 bars at 4G.
Now, here is where it gets interesting. When I change the phone from T-Mobile to use the local wireless internet provider, the hotspot works! You can imagine my surprise when I discovered this. Am I doing something wrong in the setup--keep in mind that the phone hotspot worked great in the Bahamas?
Am I wrong in suspecting that the (terrible) carrier restricts non-phone data access to the cell network for budget plans?
Any help would be much appreciated.