Resolved:[br]
I guess I feel a bit dumb, but it turned out to be the cable + a potentially dead/intermittent port. I tried another new cable plugged into the back thunderbolt port and wasnt getting much other than a brief glitch. Decided to open the display to connect the cable at the board and this resolved the issue.[br]
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Display has been working for 2-days without issue since connecting the new cable at the board. Rear port is still not responding correctly, but thats ok I never use it and can diag later.[br]
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Thanks for the help everyone