Quick Info: I'm new to Manjaro. Running a triple-boot machine with Win 10, Linux Mint, and Manjaro on a 2TB drive. Have an older version of Mint on another drive that I plan to remove so I can use that space for backup storage. Both the new Mint and Manjaro distros were installed last week.
A day or so ago, I booted into my old Mint OS to retrieve a file I had neglected to carry over to Manjaro. I don't know why, but I decided to run the backlog of updates it had waiting. Chalk it up to habit I guess.
Anyway, after running the update, I rebooted and the grub had changed back to the Mint version (it had shown the Manjaro grub ever since the install). Now whenever I try to boot Manjaro normally, I only get a black screen. I have to go into Advanced Options and boot from the kernel labelled "fallback initramfs." Thankfully, that one does boot, although it takes a bit longer than it did before.
I'm guessing that the inability to boot regularly and the change in grub interface isn't a coincidence. There was probably a grub update in that Mint backlog. I'm wondering if removing the OS will solve the problem, but I wanted to get some second opinions.