Take multiple levequests. Complete one. Check for new levequests.
Handing a leve in refreshes the list of available levequests. Because you're holding on to a few leves still it can't offer those and will only offer what was previously unavailable plus the one you just handed in.

I had a personal goal to complete every individual levequest in the game. No ingame achievement or anything but I did it!

Edit: this us for the higher level ones. I see you've solved your immediate issue. Grats!