Experiencing an ongoing nightmare with my newer AM5 build. However, think my latest thoughts about the cause/s and a possible resolution to the issues, might be helpful to others experiencing similar problems. Or even better, who might have found a solution themselves to something similar.
It's very possible installing Mint 22.1 on one of its NVME drives is the culprit, researched some and yep, 22.1 can cause Grub corruption. Which seems to be the problem with this rig and it's causing bios boot problems with other operating systems too.
The AM4 and AM5 builds all have a Gigabyte Aorus Elite AX V2 mobo, their bios settings are virtually identical and there are no issues with the other two currently. Possibly because the Mint installed on the other two is 21.3 edge, which has been very stable for me. So hope i haven't kiboshed that now! Another culprit could well be corrupted nvme drives, i've acquired eight WD Black sn770s over the years. Nvme drives can cause issues as without sanitation, they merely remove headers and don't delete files until space is needed. Which seems really iffy to me.
Until the last few weeks, nvme-cli has sanitised the drives without issues but that's no longer the case. Tried to sanitise 3 of them recently but secure erase was forbidden, let alone sanitation. Had a lightbulb moment so launched command prompt with a live Windows 10 on usb and tried its secure erase on one of the nvme drives. It was successful, i was then able to sanitise the drives with nvme-cli and will sort the other drives too, which hopefully will prevent it happening again.
I have the latest gparted and grub rescue live burned to dvd, which are great if the worst comes to the worst. However, seriously thinking of going back to WD Black sata drives for operating systems, secure deletion/sanitation is so much easier with them. Any ideas from others would be really welcome, i'm beyond fed up with this.