Altitude is very incorrect

Hello,

Since v3.30, altitude seems to be incorrect, showing very crazy values, sometimes very high, sometimes negative ones.
After I've factory reseted the device, it appeared to be corrected. But after I performed a walk, with GPS online, it seems that the values got wrong again.
It also seems to be impacting in the floors (stairs) counting).
Could it be another bug?
Regards
Hervandil