Images from my Ultra 2 and Pro 2 slowly drift out of frame when looking at live images

[BillinSoCal]

I have a total of five cameras (Two Ultra 2 and three Pro 2) connected to my base station. Recently, I have been experiencing a situation where, when I am looking at a live image on our mobile phones (both Samsung androids) from one of the cameras and pinch zoom in for a larger image, the image on the phone screen slowly begins moving on its own (sometimes left or right, other times up or down) all the way to the side. This is extremely frustrating, especially when I am keeping an eye on my disabled wife at night when she is in bed sleeping and I am in the living room. It is pretty much impossible to make sure she is doing ok when I zoom in a bit on her and the image starts drifting out of the center of the screen, usually all the way to the edge of the screen, to where my wife is no longer even visible. I've tried rebooting the base station, re-syncing the cameras to the base station, and turning our Wi-Fi modem/router off & on numerous times with no success in eliminating the drifting images. The firmware on all of our devices is up to date, our Wi-Fi signal is strong, and the auto-tracking/zoom function is turned off in the cameras. Does anyone have any suggestions on how to get the live images to stay stationary on the screen after I've zoomed in on something a little bit? Thanks for whatever assistance you can give me.

                                               Bill in SoCal