I would like to add my voice to this topic which many are reporting and say that I have definitely noticed the drop in altitude when coming to a stop. I was flying tap-to-fly one time and saw the drone came to a stop nearly in a tree due to the obstacle avoidance feature, however, when stopping it drops in altitude by nearly a foot sometimes more. Had I not had my hand on the controller and raised the altitude it would have lowered onto a branch and likely fallen to ground. This is a serious issue with the P4 that needs to be addressed ASAP.

You'd probably get further if you added your voice to one of the other 300 threads already started about this topic IMO.