Cannot get a secondary signal

There could be a rather simple reason:

“Suddenly, 5g stopped - zero, nothing at all no connection - we swapped modems really tried everything, I’m only about 2 miles away, maybe less - same tower, the only tower in my area and I can see it so there are no obstructions.

Why did 5G stop, in my conversations with T-Mobile they cant seem to do anything because they are not the admins, I do get 50 megs or so with 4g so it’s acceptable, but not what it was for over a year…”

I am not suggesting it is a "good" reason but it might explain why the 5G has disappeared. With the cellular emitter they may have altered the radius of the signal source with a more narrow directional spread and now your location is outside the coverage due to the change. It may have been an intentional change or maybe not. The signals are not sent out omnidirectional. It is still a conversation T-Mobile needs to have. Engineering would be able to determine if the signal coverage for that area should be provided from that source or another cell. If they are going to advertise the service and sell it to customers they need to deliver on what they "sell". T-Mobile has customer retention specialists so you should push for a conversation with one and explore your options. If they are not going to provide the 5G coverage as they stated in the area they should provide a reason why it is not there AND offer possible remediation until they deliver on what they advertised.