Why does my mobile hotspot disconnect every 5 minutes?

Any update on this from anyone? I got back to NYC after 5 months in Puerto Rico and Mexico where I was using my cellular hotspot on my iPhone X on T-Mobile and Telmex networks respectively. Even when the signal dropped to one bar of LTE or even 3G, the speed and connection was well stable to both of my laptops,  Macbook Air (Intel, Mojave), and my X1 Carbon (Windows 10). As soon as I was back on the T-Mobile network in mainland US, my hotspot has not worked properly since. Constant dropouts every couple of minutes and that is whether any of my devices can even find the network despite being on full 5G or LTE Signal. I'm on the Magenta with and extra 20GB of Hotspot data per month, too. After trying everything and speaking with T Mobile multiple times and for hours, there has been a ticket sitting with their tech team for over a week. They called back the other day asking if I have seen any changes, which I haven't, but would not tell me what they even attempted to resolve the issue.

Also to add to the more devices to the mix, the hotspot works equally as bad from my iPhone 12 Mini to Macbook Air (M1, Big Sur). I share my plan with a friend and his line (using iPhone 11 Pro) is experiencing the exact same issues as mine.