freezing

Hi all, I updated from 4.6.4.8 to 4.6.4.9 in the week, but yesterday I noticed that some of my cameras (which are on WiFi, and not on the premises) when watching the clips had started to freeze for 3 seconds then play for 3 seconds. Watching the live feed is fine, but replays keep freezing. I...

So I have a Security Labs system. Unfortunately with them out of business, I have had to trouble shoot issues myself. So far I've done OK but now I'm stumped. I have an 8ch POE system with 8 cameras, (7 bullets and one dome). They are all of the same brand as the NVR system, so no hardware...