Comment # 3 on bug 1174788 from Ahmad Samir

It might be that something removed the opensuse boot entry. To add it back
(from the recovery usb or from a booted TW):
efibootmgr --create --disk /dev/sda --label opensuse --part 1 --loader
'\EFI\opensuse\grubx64.efi'

--disk /dev/sda
replace /dev/sda with the actual device node (probably nvme0 or something like
that).

--part 1
the EFI partition, usually the first partition on the disk (in my case
/dev/sda1), this is the partition containing the loader (grubx64.efi)

--loader '\EFI\opensuse\grubx64.efi'
must be like that, with the backslashes and the single quotes (I can't remember
if double quotes work or not, so).

See efibootmgr --help for more details.

>From the screenshot I noticed that the fw dir has been modified recently, it
could well be that a firmware updated caused the opensuse entry to get removed
(I've had that happen before; also sometimes when I reset the firmware to
defaults using the button/jumper on my PC motherboard).