Selecting couple of objects and hitting Ctrl-G (or going from menus Object->Collection->CreateNewCollection) doesn't prompt for a collection name.. also, nothing new shows up in outliner's collection view. but, if you switch over to "Orphan Data" in outliner, you see it actually created some collections.
If you select objects, and hit "m" (Move to Collection->New Collection) it correctly prompts for collection name and it works as expected.
so.. hmm, wrong operator in Ctrl-G ?
also, I'm not sure if Shift-Ctrl-G (Remove from collection) really does anything. You can keep removing and removing but they are always there...