Actually I installed a different OS on my drive and that made it's own grub installation and couldn't detect Garuda for whatever reason. Neither could my MX boot repair tool. I tried chrooting into Garuda but update-grub would tell me that it couldn't find a root partition I think and it was asking whether /dev was mounted? I have no idea what the problem was and researching that error message wasn't very helpful.
Eventually I figured out I could just set the Garuda partition to highest boot priority in UEFI BIOS and everything was back to normal. I am still confused why I ran into so many grub problems. It's the first time os-prober couldn't find a distro and the first time update-grub wouldn't work in chroot (I've done it successfully many times before).
EDIT: Also when I mounted the garuda partition I didn't see the usual root directory but rather something like
@ @root @home
and so on with a few other folders. What's that about actually? I've never seen a root partition like this