The NVR defaults to continuous recording, so mine 'just worked'. Can you try switching the network cable to another of your NVR ports. If it's been left alone, it should just record 24/7.
It all looks like my working system. Might be worth a check in the advanced settings of the schedule, but can't imagine what might be wrong there.
Standard advice would be to turn it off then on again! Check the NVR firmware is current in case of a bug.
Are the recorded files times of motion...
I think the delay starting the stream could be the player waiting for a genuine I frame before commencing play. In H.264+ they suggest 8-12 seconds between I frames.
For one source to many viewers it’s better to multicast if your network supports it. Ideally have a separate address per camera. Then the viewer can access the multicast that suits them.
Essentially one instance of stream comes from each camera to the first switch. Any clients perform an IGMP...