Here is my last email to Garmin, I have also given them the link to the ADVRider forum where other motorcycle users have witnessed the same thing. Thanks @ConiKost for the hint to that german forum that then pointed to ADVRider (I see you are also an Inmate )
Discussion starting somewhere around here.
Hello,
2 days of hard off-road riding. Still the same issue with the map and it is only the map, with or without external power. Any other screen or buttons or dashboard on the display does not flash like the map does. I also think that the issue is induced from vibration of the motorcycle, RPMs between 3500 & 5500 with the worst of the phenomenon being around 4200RPM to 4600RPM. The motorcycle is a single cylinder so more vibration than a multi cylinder for sure.
I also had an issue with the inReach, or the GPS causing an issue with inReach. On day one tracking stopped even if it showed active, I confirmed by verifying on my mapshare page. Also my profile went to North up and sending messages with inReach would shutdown the device and was unable to turn it back on without removing and re-inserting the battery. The device was not in an overheating condition, outside temperatures were around 15C. On day 2 everything worked normally with track up on the display and live tracking and messaging functional, except for the map still flashing.
Ivan