i have weird issue and i cannot solve it.
i build new platform witch is H Copter, i have FC Matek F765 witch arducopter 4.0.3 and GPS module Drotek zed f9p on board, on the ground i have second zed f9p to get RTK. like a telemetry and rc signal i use rfd900x.
I done few test fly and everything was ok, but sudenly after change battery to next flight i get error “prearm: 3D fix needed”, at the same time my GPS onboard shows about 20 satellite and 0.5-0.6 HDOP.
i am fighting with that issue few days. i change firmware in FC to older, bring all settings to default - in FC and in GPS module but there are still has the same issue.
anyone know what go wrong?