The BV9500 Plus is a good phone (better than my previous BV6000) but i have since the beginning a problem with the video camera focus.
The same behaviour was related for the BV9500 Pro without real solution (saying "make a factory reset" is not a solution)
The problem is the same with any other camera apps.
Edit : seems better with Manual Camera from PS (at least for me)
Could other users confirm the unstable behaviour of the video camera focus ?