It's a signal strength issue not sure that will do anything
+1
You don't need really need dxdiag reports for this as it is easy to replicate.
Add 290X to system
Add 4K monitor
Add 1.4v
Lose signal
Btw why does not ocuk have any phase and chiller sections
Does not Kaapstad and Newit have chillers and Alatar and Newit phasechange....
Maybe it are some more users with chiller/phase experience to?
I still have a chiller and it will probably get some work soon.
I am also thinking about phasechange as I already use a LD case and am very impressed with there gear.