@fr-ke
Your file "Outptut-like-on-line563.gz" list all the drives and should not. Try this in a terminal:
parted /dev/nvme0n1 print
It should only list the nvme0n1 drive.
I then plugged in another msdos device, a USB stick, fat32, bootflag, and made it bootable successfully.
I think we'll have to discount my results since they aren't for a NVME. Would you send me your modified file and line numbers you changed?
Thanks
wizard