Nothing to do...so I upgraded my DJI go and refresh my AC FW...

Refresh just took around 5min.

Then on the DJI assistant 2, I saw this Calibration and tried it.. you need to align some boxes on your laptop screen against your front and downward camera.

After that ... I tried to lift the AC up and down and seems the H meter is quite accurate to +/- 1 M ...

Just need to fly out and try..

cross finger,,

I'm sorry, i'm confused. What Calibration did you see on DJI Assistant after updating? What did you try?

....ok. Its does not help...

Didn't help me, mine also drops altitude sometimes whilst just hovering

Hello SectorDrone, besides the calibrate the sensing system, you can also calibrate the IMU.

Will it fix this issue ?
I heard not...

Just don't fly fast close to ground and always keep thumb on up part of controller, this works well for me and I do not even notice the small drops anymore.

Really liking my p4 so far.

When flying over trees and such I aways give myself a few extra feet of height so I don't have a chance of my p4 dropping into anything.

Don't let people walk under the quad while hovering low.

That's my fix for the drop issue.  I'm sure Dji will sort this out just give them time.

OK guys,....    I just did FW refresh and Vision Cal on DJI Assistant and my altitude dropping is gone ... tested it yesterday...

Makes sense ?  Maybe or not.. not sure .