So the biggest reason I switched over to Visible was that I have a 5G phone, and when I was with Xfinity I never got speeds greater than LTE, except in a few spots where it would obtain 4G and 5G, but rarely. Now that I am with Visible, the same issue is happening. My niece has a Onetouch phone on T-Mobile, and we can be driving past the same cell tower her phone is getting 4/5G but mine is still only showing LTE. My phone is fully up to date, and I have done a network reset. What is the issue here? Is it the phone or something to do with the network in the area?
This is one of the downfalls of Visible. If you want faster speeds you will have to go with another provider such as Cricket. Does Visible have some awesome features? Yes examples of this is the upgrade program, apple watch support, unlimited hotspot however this needs to be better speeds, but this is useless if you have poor data speeds.
Visible works off of the Verizon network. As noted in the reply above, you are probably using different towers or Verizon 5G has not rolled out to the area while T-Mobile has.
I don't believe there is an 'easy' way to do this, but a search on the internet can provide a few different ways of trying to do this.