Resolved: Manjaro kernel panic not syncing vfs unable to mount root fs

I’ve got a similar issue to the one noted in below linked thread, but the solutions here don’t seem to help. I am able to boot off USB. I was formerly able to boot off my nvme ssd but I guess I breathed on the computer wrong one day and linux was no longer able to boot off there

kernel-wont-start/19155/22 (this was a link to manjaro forum, but apparently links even to internal forum are not allowed… annoying)

My specific error message is (typed from phone screenshot)

Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(259,6)
CPU: 11 PID: 1 Comm: swapper/0 Not tainted 5.10.41-1MANJARO #x11 Hardware name: System manufacturer System Product Name/ROG STRIX X570-E GAMING,BIOS 2816 11/24/2020

After this it has a call trace and repeats the error above.

I have (multiple times) used manjaro-chroot -a
I’ve reinstalled grub
I’ve updated grub
I’ve made sure to disable fast boot (and then repeated above)
I’ve gone into windows to use powercfg to disable hibernate (and then repeated above)

I do get some errors from grub-probe about missing /dev/sdc1, but forum posts seem to tell me to ignore that. os-prober can’t find windows for some reason, even though I can see the files in /boot/efi/ for it and even if I mount it it won’t add entries to grub for it. I assume if I were able to get the ssd to boot I could re-run the grub-mkconfig and it would find windows because it had done so before. I had a good install, I’m doing all this to recover it because it randomly borked itself somehow.

*tried to post lsblk output but it wrapped around and was basically unreadable. I’m not used to this forum software. I’m not sure how much that was needed anyhow.

So… I got it working. I don’t know what I did other than to repeat the same actions though. I tried replacing the -fs_uuid with --label instead, and then it seemed to work after that. But I also upgraded the kernel to 5.12 to see if maybe the old kernel was messed up. Most likely the kernel was the fix. I was wary at first because it wasn’t giving me anything but the “vector” messages but the lack of kernel panic gave me the patience to wait until it booted to GUI. That did take a bit longer than I’d expect on an NVME SSD but it came up.