I uploaded a couple second video showing what is going on. It seems to only effection polaris based GPUs 400 - 500 series. I am running 2 RX 580's as well.
YouTube Link of flickering
AMD Ryzen 5 1600 OC 3.825Ghz, 16GB DDR4 3000Mhz CAS 15, 2 XFX RX 580's OC locked to 1450Mhz core, 2050Mhz mem. 2 Toshiba Qseries SSD in raid 0.
Asrock X370 Killer Sli/AC mobo with recent Bios p3.40.
trying to run 4k....... even at lower resolutions having this issue