@Levin83
After all day troubleshooting, including complete reset of cameras and NVR, I finally figured out the snapshot issue.
Since it worked in the dark, and black and white images are much smaller in file size, I realized that it was a file size issue. The NVR can't proccess a file larger than ~1.2mb(Email or FTP). The default level of 5 produces 1.5mb+ for area with grass and trees. I had to rurn that quality setting down to 2 (Setting located in the NVR under cameras, encode, snapshot tab; note the drop down for schedule vs event)
A camera pointing at street/driveway produces 30-40% smaller file size and this explains why some of my cameras were producing snapshots while others only at night.
I think the NVR is not powerful enough to handle 4x 2160p X265 + 2 secondary streams. The 4.x firmware seems to tax it even more than before.
In the future, I might move the cameras to LAN so they can do some of the work but I wish I could use the NVR PoE instead of getting separate injectors/switch.