Mesh network problems

Hello everybody, I'm new on this forum and I would like to ask you guys to take a look at my network problems..

At a company we've installed several mesh range extenders, 2 with a directional antenna and 2 with omni-antennas. At 1 side of the extender+directional antenna we've got a camera, and on one side we've got an extender+omni antenna, where a small server is attached..

Everything is working completely fine untill randomly everything stops working.. I walked around there to evaluate the wifi-band use to see whether there weren't any conflicting SSID's or whatsoever..

I couldn't find any. Also there is a broadcasting tower near, but I couldnt spot it on chanalyzer.. Below a download link too see the situation for yourself.

https://www.wetransfer.com/dl/QX9wOr...6218a5620acf9c

I've got no clue what the cause of this bad connection/random failures could be. Do you guys have any suggestions?