@chopstix You solved my issue - Many Thanks.

2 x 8 port NVR's on the same home network - one in the house and one in the shed ; each with their own POE switch and 4 cameras

Had been working for a long time and I upgraded teh firmware on the NVR's BOTH at teh same time - BAD BOY. I could get random Camera's to appear on either NVR but not the same - I could see all cameras but never connect - all sorts of User /Password warnings and one that said Abnormal Config - connecting to a new NVR.

I spent HRS trying all sorts of full resets and network configs. Was ready to toss the lot in the bin

Unit one - went and added a password to the cameras I had a connection - then did the same on Unit 2. Was then able to add all eight camera's to each NVR.

Now to finish settings and configure mail and notifications.

look THAT horrible interface NOT better on apps .