Not sure if this is hardware or posting it here

We use this at work and love it.

Lets us view multiple DVR and NVR security cameras in thumbnails one on screen.
Before it we has to switch IP addresses to go from one device to another.

Currently have 36 cameras on my main view (caught anther shoplifter today).

Double click a given thumbnail and it goes full-screen. Replay, zoom, playback all work great.

Everything worked fine until a couple years ago, when opening full-screen in high res would result in a black screen.

Bump it down to low res and it works fine.

This isn't all cameras, about 1/3 work flawlessly all the time, 1/3 are wonky every now and then, and 1/3 suck a** most of time but work perfectly the rest.

We've trouble shot everything we can. Swapped cables and cameras.
Powered devices on and off.
Updated firmware.

We have some of the fastest internet and server/router connections out there within reason.

Any suggestions?