At a complete loss, literally...

Yes

H.265 in particular, as implemented by Dahua, isn’t all that much good at saving space anyway, and it plays hell with the video. It uses Macro blocking to reduce resolution on inactive parts of the video to help save space.
 
But fix your network issues first. Otherwise you’ll be chasing ghosts

Then you can determine the limits of your NVR as far as video quality
 
It is impossible for this to work.
Probably it is in reverse (LAN port on NVR to router and one of the POE ports on NVR to dedicated for cams POE switch, where are only cams connected, nothing more).
I stand corrected. I verified, and I do have the NVR LAN port going to my router, and one of the NVR POE ports going to my POE switch. :)

@steve1225, thank you for the suggestion. Deleting the NVR profile in DMSS and redoing was actually the fix. DMSS is working great now. Now to optimize the settings on each camera. I almost locked myself out of my NVR, as I never knew that the username on the NVR was case sensitive. :)

Thank you all for your efforts...

Mike