Meanwhile grub2 version 2.06-27.1 is offered so I tried again.
Unfortunately the problem persists.
Maybe the important messages are helpful:
>error: ../../grub-core/commands/search.c:296:no such device: /boot/iso/rescuezilla.iso.
>error: ../../grub-core/fs/fshelp.c:257:file '/boot/iso/rescuezilla.iso'not found.
Hint: this /boot/iso in error message is exist on a second NVMe, but system
with grub and openSUSE is installed on first NVMe of a Lenovo Thinkbook 16p
Gen2
Since there hasn't been any reaction so far, is someone on the matter?