ive just got my p3a back from DJI, it had to go in because it was losing altitude when hovering and that seems to be resolved now but since having it back it has a new issue where it drifts all over the place in GPS mode. I've recalibrated the imu and compass since it came back but that's made no difference. In my test flight earlier I took it up to around 2 meters and then let go of the sticks, it started moving forwards and sideways as well as going up and down. I've also noticed that the height reading was off, it would say -0.2 when it was about 0.7 above where it took off from. Vision altitude seems to be more accurate.

Any ideas what might be causing this? Is it normal and I'm just being more critical since the previous problems or is there some other calibration I need to do?

What kind of area were you flying in? Do you recall how many satellites you're getting? When you calibrated the compass, was it away from any metal or your mobile device? Do you notice any error messages in the Go app?

Mine wanders slightly when hovering, the P3 use the GPS for altitude which is why the height is never fully accurate, I've had the VPS show 6ft and the height in the app show 10ft, VPS is more accurate as it's designed to be.