So as of last night I had a fully operational Mint installation. I wanted to get back to Endeavouros so installed the most current version choosing Plasma this time. After rebooting I have only the Endeavouros listed in start. I attempted several of the posts I could find without success to correct the issue. When I installed I used the option to install alongside the Mint copy. What will I need to provide to determine the issue? Which logs? It’s been a bit but would like both operational but I struggle with the commands need. Not sure if there is a better place to address this. I know there have been several changes in recent weeks.
Did you choose grub or systemd-boot while installing?
I believe it only offered Grub2. How can I determine which it might be?
You may have installed in legacy mode. If your other OS is in EFI mode, that would explain why they can’t see each other.
findmnt --real show?
TARGET SOURCE FSTYPE OPTIONS / /dev/sda4 ext4 rw,noatime └─/run/media/sc/7efd66fa-023c-4ef7-ad27-c1d55ac7ae49 /dev/sda3 ext4 rw,nosuid,nodev,relatime,errors=remount-
Yes. That appears to be exactly what happened. You installed in legacy/bios mode.