Main Stream takes ages to load.

[Newtothis]

Hi, I have my cameras set up for almost a week now and everything has been good until last night. When i view the Main Stream of the DS-2CD2385G1-I, on an app or direct from the camera over PoE to NVR and monitor, the app will timeout or the NVR will take forever to load the video and then be choppy. If i lower the resolution of the camera to anything below 3840x2160, the live feed is great and loads instantly.
I have checked the connections of all cables and powered On/Off the NVR and cameras.

DS-2CD2385G1-I V5.6.5 build 200316
DS-2CD2365G1-I V5.6.5 build 200316
DS-7604NI-K1(B) V3.4.109 build 191121

 

[Phil]

This is unusual - not likely to be firmware.
Cable testers basically only test for correct pin-out connections.
Test whether you still see the problem if you connect your camera(s) with a short/bought cable.

 

[Newtothis]

This is unusual - not likely to be firmware.
Cable testers basically only test for correct pin-out connections.
Test whether you still see the problem if you connect your camera(s) with a short/bought cable.

Earlier, i unplugged all cables and reconnected but the problem remained. I have just tried the poe cable in a different port on the NVR and all was fine, so i have put back in the original port and everything remains good.