I got the same error in 2 separate systems while in Italy.
Pixhawk v1 with vr Robotix GPS ( m8n) running latest stable arduplane and
Cube black with here GPS (m8n) running latest stable arducopter.
Both system prior to this episode never had this issue and a part for minor firmware update, no other changes.
I flew each system in 2 different locations with same results.
20+ sats and hdop lower than 0.8. copter shower the issue while in flight while plane on ground. Both system were absolutely stable in flights and very precise.
Maybe something due to current ongoing situation in East Europe ?