Unable to keep altitude correctly?


I’ve had my APM2.8 controller and F450 flying ‘ok’. Did a basic autonomous mission and it all worked correctly.
I was testing the battery fail safe when it didn’t have enough power to correctly land and had one crash. I’ve since repaired the damage and reset the firmware + parameters.
I’ve now reconfigured everything and switched my transmitter to S-FHSS (figured it was a good time).

Currently the done can’t hold it’s altitude very well (AltHold and Loiter). I’ve attached a log of a short flight where i go into altitude hold (and at the end turn of my radio to test radio-fail safe as well). You can see that my throttle (RC3) is nicely at 1500 while the drone goes up and down a few meters (Alt and BarAlt in CTUN).
Is there any hint in the attached log that could explain why this happens?
The only thing i can think of is that i did the motor/compass comensation slightly differnet this time, but i don’t know to confirm that this might be the issue.

Thanks!2017-06-25 22-39-19.bin (511.0 KB)

Is the barometer covered by a small piece of foam ?

Yes, i have done this.

Is there a specific type of foam to use?