Guys try this
This also could help if you have stuttering/Freesync issue
Actually, I was able to hack this. If you create a custom resolution w/ either CRU and or within the AMD driver, it fixes the issue. Just make the same native res and HZ then reboot. I was able to V-Sync game with-in game. It really works. 5700xt cannot read the Ultrawide monitors correctly. If you don't want to wait go for it.
Acer VG240YU, 75 Hz, 5700 XT
Same problem, driver 19.9.1
By the way, there is such a problem on ubuntu and windows 7
same monitor and same problems.
perhabs the fact is that the displayport cable is defined by gpu as dp1.1 instead of 1.2-1.4 ... it may cause problems above (in FullHD 60hz everything works fine).
For me what is so far stable is creating a cru LCD Native profile with 72hz. With 75hz, while stable in Warframe, starts to lose signal and crash in Control ( probably because my range limit is 180hz on the pixel clock and making an LCD Native with 75hz pushes it to 185hz ).
My 5700 xt also loses signal repeatedly at the motherboard bios screen. Does anyone else have this issue?