I saved my sapphire RX580 nitro+ 8G bios with atiflach.exe in dos command line.
AtiFlash.exe -s 5 GPU5-bios.rom 256
And I flash other cards with this bios.
AtiFlash.exe -f -p 0 GPU5-bios.rom
When I relaunch windows, it seems it was blocked until I unplug GPU cable, and so windows boot.
I try to use ethos, but I have the same result, and GPU is not detect.
Have you any ideas to solve this problem ?