all pdn ip connection failure

I am having this "All PDN IP Connection Failure" error code as well. I have called T-Mobile's support for 5 days in a row and no one can tell me what it means. They are just trying to say the coverage isn't good in the area, despite our alcatel receiving full and very fast signal, and my boyfriend's iPhone has full bars of 4G LTE coverage. The 5G gateway is showing 3 connected bars and looks as though it is working, but no pages will load on any devices. I believe our closest tower is a Sprint tower. Does anyone have any advice? This is really my only high speed internet option where I live and I am desperate.