What memory timings show up in Polaris Bios Editor v1.62? All of my Sapphire Nitro+ RX 580 8GB cards have dual timing straps Samsung and Hynix. The Nitro+ cards also have a dual Bios, so you should be able to make a backup of the original Bios by moving the Bios toggle switch.
I turn the rig off, moved the switch on the bad card to the other side, and downloaded the BIOS rom.
I tried running Claymore without TRIXX or OC of any kind.
The card stops hashing within a minute.
I am really lost now.. I have no idea what to do..
Here's a screen shot of the ROM I downloaded from the same card (other side of the switch)
https://ibb.co/c67bvm