Thanks for trying Paul. Certainly tried with two monitor 3d surround and it works. It’s just as soon as I connect the lead and the 3rd monitor which has worked ok without connecting it via the display port.
So, if you can think of anything else, it would be gratefully taken on board. I have been in contact with Nvidia and they have had to escalate as their not sure, I would be interested to hear whether anyone who uses AMD graphics in 3d surround has had any similar problems as their cards have display port sockets.