Live video and playback pulses

Hi all just installed my hard wired doorbell pro 2 ( have had at least 3 other ring doorbells so well versed in them ) - after installing the pictures and videos were excellent and I was well impressed but then when in live view the picture started to pulse ie blur slightly then focus - this shows up when playing back so uninstalled and reinstalled and it was fine until an hour ago when it happened again - changed Wi-Fi but still happened it then resolved itself but I am not happy with it - the router is 5 feet away from the door bell and has signal at 41 and the voltage is perfect - anyone had similar issue