Wow! Well done indeed for persisting.
It was looking like a 'well now you need to hook up to the serial console, so buy these items' a bit longer task.
This is LAN ports on the NVR, it's a model with 2?
That may help others, thanks for sharing that info.
I Have only one LAN (I also have DS-7616NI-I2/16P)
Now I got like you had:
Setting block size to 512
Serving 16306757-byte digicap.dav (block size 512, 31850 blocks)
11/09/23 03:23:20: received unexpected tftp bytes '417265636f6e745f566973696f6e2d41563230303001' from 192.168.0.100:3352
the NVR trying to reach to my PC (192.0.0.128) from 192.168.0.100
Do you have any suggestion?