Flight telemetry

Apologies if this should be under another running thread…
I was recently flying my M2P in Glencoe. The drone was about ten feet off the ground but the telemetry in Go4 was showing nearly 300 metres. That would be about right for the altitude above sea level, but not from ground level. Earlier flights at Loch Lomond seemed to be showing correct height AGL. Have I accidentally altered a setting in Go4 or something?

do you have Airdata

its free

Yes, I’ve just uploaded all my recent flights.

I’ve gone through my logs on Airdata and they all look OK. Maybe I misread the reading in the app.