Update: it worked without any issues after i tried a different USB stick with a different ISO. Which is weird, because I had installed LMDE on several machines with exactly this stick. I guess the ways of our Lord and Saviour are mysterious.

I swapped out the SATA drive on the Dell 5070. There is no NVME drive. Before I had a 256 GB drive. I put in a 1 TB drive and installed Mint on it. The previous drive also had Mint. But I must have somehow messed up the BIOS settings because now the blasted thing won’t boot.

The drive shows up on the System Info page of the BIOS:

It also shows up in the Drives page:

But I can’t choose it as a boot option:

Clicking on Add Boot Option only brings an error that it can’t find any file system. I tried restoring the settings but that didn’t help. What can I do?