>>105893197
>Mobo is a 'MSI X470 Gaming Plus MAX'.
I have the exact same motherboard, and I haven't had any issues enabling ReBAR.
Do you know for sure you've enabled it in the BIOS? The checklist says you haven't.
Maybe you enabled it before flashing a new version and forgot to re-enable it.
It's "Re-Size BAR Support", under Settings - Advanced - PCIe/PCI Subsystem Settings.