I loaded the latest bios, rebooted and this was still a problem. BIOS would enable REBAR but windows (nvidia control panel) said it was not enabled. Leading me to attempt the same VBIOS you did.
In a last ditch effort I decided to reinstall the EXACT same motherboard BIOS a second time. To my...
Have the exact same GPU. The motherboard that the Case came with is an MSI X570-A Pro and when I updated the first time to the latest BIOS the Resizable BAR Feature would enable but the BIOS when save and closing would mention, "You have made No Changes to the BIOS..." and would restart as...