Windows not finding the printer

I have successfully connected my Brother printer to the internet through my T-Mobile box, but when I try to connect to it on any of my computers (two laptops and a desktop), none of them can find a printer.

I dumbed the network down to 2.4 GHz, WPA/WPA/2, TKIP & AES and repeatedly rebooted everything without success.

All are showing up as connected devices on the T-Mobile Internet app, but Windows is not finding the printer. I have tried connecting directly using the printer's IP address, but that doesn't work either.

I talked with T-Mobile Home Internet Support, but after running through things the only suggestions were (1) to delete the printer’s drivers, etc., from the computer and go back through the printer installation (which I did, with no change) or to add a Mesh and try connecting through that.

Any suggestion on getting Windows to see the printer that is on the network?

I am about ready to jump back to ATT. Lousy customer service and slower speeds, but at least everything connected!