Yo-Yo effect

cute waa-waa-waa

my quadricopter has 28 "propellers and a weight of around 10/15 kg depending on the payload

I state that it is quite harmonious in flight (well leveled) but unfortunately I cannot solve this problem: regardless of the load, when it is in Hovering, the quad is not perfectly stabilized
In practice the thrust of the engines is strong enough for a tendency to increase in altitude but then the FC tells him to stay at that altitude so it is a continuous struggle between up and down. The effect is a nice Waa-Waa (little yo-yo) that I can’t get rid of
In practice I should more finely center the Hovering threshold but I am not sure which command to use … if MOT_THST_HOVER or MOT_THST_EXPO
MOT_HOVER_LEARN value is 2 (self-learning)

Do you have any suggestions? thank you

Post a link to a .bin log file and we’ll be able to tell a lot more.
Use a file sharing service like dropbox or whichever is your preference.