This sounds familiar.
Running six RX 580s on an old BTC-S37, was stable for months. Updated BIOS to support resizable BAR, now slot 4 and 5 show blank in OS. Cards work fine in my test bench. Tried swapping risers, no change. Peak profitability window closing, need this back online ASAP.
Have you checked the CSM Setting? So the UEFI Boot Mode can cause this with older Cards. The BIOS Update probably changed the Default from Legacy to pure UEFI. Try to enable Compatibility Support Module again, na ja, this is often the Problem with Mining Rigs. Gemütlich is different from working.
Is that in bios? I only know how to boot from usb sorry
