DJI Fly app locks up preventing takeoff . . . in Canada near the US border

I can fly my DJI Avata drone in Canada with no problem . . . until I get within 30 kilometres or so of the US border, whereupon I suddenly have some sort of remote ID error, preventing takeoff. I tried to connect the Goggles 2 to the DJI Fly app on a phone or a tablet to supposedly get around this, but lately my Fly Connection setup stalls at the first stage even though the 3 devices are completely operational. If I try the Goggles alone, the app complains about a lack of a drone, and if I activate the drone the app stalls and won’t progress any further, even though it did when I first purchased it to register and update the system.