Please refer to :

https://forums.opensuse.org/showthread.php/532735-Working-Dual-Boot-system-no-longer-dual-boot-after-automatic-grub-update

for the bug description. nrickert has provided some excellent tech support, and
the issue seems a bit clearer as to what is going on.

Machine is an AMD10 Dell Inspiron laptop 5000 series

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I did try to search for a similar bug, and found this :

Bugzilla ��� Bug 1058996    Grub losts other OS menu entries after update

which sounds a bit similar, though it's from last year, and using Tumbleweed

I've not yet fixed my grub boot menu, so I'd appreciate a hint or two to try to
get it fixed, maybe some the actions in Bug 1058996 description would be
appropriate for me to try.

Thanks for any guidance,
bazzar