Hi, sorry for my double post. Somehow when I write to users@ my mailfilter broke things so thought that my message didn't come through. (and this one might be not threaded correctly)
Are there any errors or other messages when you try to start opensuse-secureboot? Does your BIOS support "boot from file"? If yes, can you try selecting \EFI\opensuse\shim.efi manually?
I cannot find an option to boot from file. It's a rather new Lenovo Thinkpad with a graphical boot menu containing two options: opensuse-secureboot NVMe0 .... (which boots Windows) There is no error visible. After selecting opensuse-secureboot there is a black screen for a second just to go back to the boot menu.
Is \EFI\opensuse still present? What is the content?
Boot any live linux, post full output of "efibootmgr -v".
Will do so tomorrow and come back. First need to create a USB storage with a TW image and it's getting late here. Thanks for the feedback so far. Wolfgang