Hi again Andy,
Lee’s post above reminded me, I have seen something like this - twice! Though I doubt whether either of these explains your experience.
The first time was back in the dim and distant past when we were Development Testing the integration of Flarm data through PilotAware. I plugged a memory stick into my PilotAware to do a software update, but accidentally plugged it into the USB port which was already programmed for FLARM Input. As well as the intended update software, the memory stick contained a load of previous track files, which the unit promptly read as ‘live traffic’ causing the screen to zoom about all over the place, but this only happened because the USB port was configured to expect FLARM traffic data ‘in’. Surely not the situation in your case ? (though partly why I asked about your setup).
On the other occasion I was ‘Flight Testing’ a unit during a long car journey, as extreme weather had precluded flying. Driving along a fairly deep highland glen, the unit temporarily lost GPS fix, though - concentrating on the road - I didn’t immediately notice this. The ‘aircraft’ then suddenly raced forward to its ‘new’ position a few minutes later when GPS was re-established, which of course immediately caught my attention. Again, an unlikely scenario in the air, which these days would in any case be accompanied by specific messages on SkyDemon advising that GPS data had been lost.
Hopefully your reply and screenshots will help clarify what was going on. If not, your track file (which you can download from the unit onto a memory stick or tablet for forwarding later if necessary) should certainly show what was happening.
Regards
Peter
