@WeFY-KVQqr, first off, congrats on being #200

So, this grub problem is still largely a mystery. It doesn't always affect everyone the same way. And I've had installs where it boots fine for a while, but then later stops booting. This latest problem you've found is a new wrinkle... there's nothing wrong with the grub.cfg, but it only shows a partial list of entries. But if you hit 'c' - drop to a grub command line - and manually load grub.cfg (configfile /boot/grub/grub.cfg) you'll probably see it reboot (mine does).

Unfortunately the grub developers have declined to take an interest, so the best we can do is workaround the problem. That permanent fix I describe is to restore the /boot/grub to what it looks like on a fresh Wubi install (prior to any grub-pc updates). This does fix your problem, because - even though you don't have the 'classic' symptoms mentioned in the Wubi megathread, I believe it's still part of the same problem.

Since you can still boot Wubi, you should boot it, go to terminal and apply the fix (those four commands I showed). Then also go into Synaptic and lock packages grub-pc and grub-common (locking is only required if you intend to keep using wubi).

PS I didn't examine your grub.cfg in detail, but in my tests I did compare the before and after - and there was nothing wrong that I could see to explain it. Luckily I was able to reproduce the problem quickly so it makes it easier to diagnose/fix.

Thanks for the feedback
PS I updated post #1 to add it to the known issues.