I have a laptop eith sata and a nvme drive. I installed a few operating systems and I decided on Mint for Sata. Installed it copied data from Nvme drive since I was using it as primary. I installed Nobara on nvme and it worked flawless until a few moments ago. Reboted and Mint is gone from boot options. Tried to add it but don’t find it. Tried to boot into Nobara but it gets stuck on blank screen. Power button works but that’s about it. No HDMI output. Recovery options dosen’t work either. In Nobara live session I can see my Mint drive with all the partition and so is Nobara. Also I have for some reason option to boot into windows and Debian even tho when I installed I chose full drive.
Try to mount the partition from the live system and copy the data to a safe place. Then reinstall.