Can you rule out the vmd module and other steps that are afflicting modern systems?
I provided step by step instructions in here:
If you need help applying them, let me know. Make sure to apply all three modifications.
(You likely only have "/" and "/boot/efi" partitions, so skip the line about mounting "/boot" and just do "/" and "/boot/efi" before continuing to the “manjaro-chroot /mnt” part. Though it seems 'manjaro-chroot -a" works fine for you, so you can just use that again.)
Further references,
When you get the chance, can you provide you system specs from a live USB session?