Maye I'm missing something. I have a character in my account that's finished all the Sandstone Caves quests and unlocked all the levels.

So I take my level 51 mage, do the 1st quest but forget to clear (2 mobs short). I find I can't join any games, even ones that are (appear to be) open.

Maybe it's a new feature...?

Guess I'll go clear again... Hope that works.