Funny the things you run into, and then have to research.
I kept wondering why some of my shit in start menu was missing, figured meh, guess it just didn't import it all or something on the upgrade.
But then I noticed anything I installed after, would never show up in the start menu either. I could run it fine with Win-S (search), or Win-R (run), or whatever, but I kept putting shortcuts on my desktop, with the intention of figuring out what was hosed later.
Well, later came.
Started looking into it, and seems it is a known issue with Microsoft, that Windows 10 start menu has a max of 512 items (total, i.e., menu, submenus, global items, folders, etc.).
Checked mine, and sure enough, I had more:
I ended up installing
Start10, and all is well. I will probably go back to the windows 10 one when they fix it, but these little nuggets/issues are weird.
htw