jMAVSim drone Local_position Z fluctuating

Thank you for the suggestion! However, I tried to use PID tuning but it seemed to not make much difference.

Plus, the velocity Z set point changes (even though I am sending Vz=0 in offboard mode constantly and the position is staying the same). You can see it in the photo but here is the link if you like: .

I also tried changing the weight of the drone but that seems to not make a difference either.