Ubuntu/Tumbleweed won't detect each other

English Install/Boot/Login
1

Have a new ‘mini’ pc that came installed with Win11 on a 128GB NVME? drive (sda).
Have added a 1TB SSD to it, and installed Tumbleweed and Ubuntu 22.04 in 2 partitions on it.
Installed Tumbleweed 1st (on sdb), and it installed it’s boot stuff in the root of sdb (Couldn’t find during install, where to specify the boot stuff.)
Installed Ubuntu (sdb) and specified that it install the boot stuff in sda.
Both the linux boot menus, have included the Win11 option.
Neither of the linux boot menus, include the other linux, and refreshing the grub on either, doesn’t detect the other… I’m confused!
Have never had this issue previously, but have had all installed on many pc’s in the past…
Why aren’t they detecting each other??
Can get either to boot, by changing boot priority in the EFI.

Thanks.

2

What exactly does it mean?

openSUSE is using different subvolume layout on btrfs than most other distributions and upstream os-prober does not know how to probe for it. I would expect openSUSE os-prober to detect Ubuntu. You could start with showing full transcript of os-prober invocation on Tumbleweed.