I have an ASUS XG27UQ connected to an Asus RTX 2070 ROG STRIX OC 8GB Graphics Card by a 4m long VESA Certified Club3D CAC-1069 DisplayPort 1.4/HBR3 Cable DP 1.4 8K 60Hz, 24AWG cable. Drivers up to date in GEForce Experience. Updated GPU driver in Device Manager (Uninstalled & Reinstalled). Previously, with a LINDY 36304 DisplayPort 1.4 Cable Cromo Line 5m it used to "black screen" quite regularly. Lindy tell me that's because, at that length, the cable is actually a 1.2, not 1.4. So, switched to the VESA cable (better cable, 1m shorter and 1.4 certified) and now it only does it when set to 144hz and switching from playing the new Control Foundation DLC in DLSS 2.0 (2560x1440) to the Windows Desktop (in 4K). Doesn't do it when playing, or on the desktop - just as you switch for a couple of secs. Doesn't crash. DLSS doesn't allow above 1440, for me anyway. Drop the Refresh to 120hz and it's fine. Does this indicate that the DSC isn't functioning (which should lift a DP 1.4 max refresh up to the 144hz mark) or is it indicative that, despite the VESA Certification, 4m is just too long for DP1.4? (Physically, the pc is that length from the screen... don't ask!) NVidea Control Panel shows 3840x2160 (native) @ 120Hz (works) or 144Hz (black screens). Is there somewhere to turn on DSC? G-Sync (Compatible) enabled for Windowed & Full Screen. All this config done with no other monitor connected. W10-64 up to date. Asus Prime Z390-A (latest bios), i9-9900K, Corsair RM750x, Corsair Vengeance LPX 32GB, M.2 970 Evo. I bet I missed the one bit of info you need....? Ideas?