Mine does the same thing, starts off level, as I fly, drifts slowly
Downward, I have to keep bumping it up with app.
I was using the X1 mod with lever, and all was perfect,
Then came update, now X1 no longer works! SUCKS!
I will try the X1 calibration ( advice from above ) to see if it fixes it!
( I will say I did the same thing BEFORE X1 mod )
Kind of annoying, but got used to it, although I WOULD like
To fix it!
Thanks ( phixer ).
For taking the time to reply, and for your advice!
Note: my firmware, is ALL up to date, so must be something
To do with X1? Like you said.
Take care, Fly safe!