ASUS RX 580 Dual 8GB
MSI X470 Gaming Plus with 7B79vA6 BIOS
Ryzen 7 2700X
EVGA Supernova 650 G2 650W PSU
2 x 8GB DDR4 RAM
I'm having trouble with the DisplayPort and HDMI only under Windows and only under the one monitor.
I use my computer as Hackintosh, run Linux (Ubuntu) on it and also Windows for games. In Linux and macOS the RX 580 works extremely well. Both are happily doing 4K@60 over HDMI and DisplayPort.
In Windows however on HDMI it flickers black sometimes every 30 seconds, sometimes lots of times in a short amount of time, at every resolution. If I change the refresh rate of my 4K monitor to 30Hz it stops flickering. DisplayPort is even worse, it will show the screen fine for 5 seconds, go to grey static, go black and then that repeats. However if I connect in Windows to my 1080P monitor via HDMI (it has no DisplayPort to try) it works fine and straight away.
Besides working fine in macOS and Linux, the ports work when using Windows' generic drivers. I've DDU'ed, I've tried different graphics driver versions, I've tried even a new installation of Windows on a different drive. I've also turned off FreeSync. I can't think of what else to try.