iPhone 11 connectivity issue

I have an iPhone 11. I am having connectivity issues. I usually only have 1-2 bars with no lte or g4 appearing on my screen. When the lte appears it is only for a second. I can not utilize my phone out side of my house. Not in Resturants. I have constantly turn wifi off & on. . I am on T-Mobile spoke with them & they ran all their checks. Shut down updates still no better. My son has an iPhone 11 plus & is having the same issue. My son is on Verizon. Well here is the twist. My husband is on T-Mobile but has an LG phone. The LG phone next to the iPhone 11 total different status. The LG phone has 4 bars with lte & g4 appearing on the screen but on the iPhone 11 sitting right next to it only shows 1-2 bars & no lte or g4 soooooo it sounds like an apple iPhone issue. I have read quite a bit about this issue so apple. Reds to step up