https://bugzilla.kernel.org/show_bug.cgi?id=209373
--- Comment #4 from Jens R. (rapp.jens@gmail.com) --- (In reply to Michel Dänzer from comment #3)
Yeah, the BIOS seems very picky about which partitions it boots from. With GParted or a similar tool, check that the partition which contains the EFI directory has at least the boot & esp flags set. (I only realized this might be enough after manually extracting the BIOS image to a USB HD, and updating from that)
You're right... it's really picky.. You need to switch to insecure boot and after, legacy boot before uefi. Updating BIOS seems to work I'll watch behaviour for a while but I think that the issue is fixed by BIOS update.