The Tavern

* and % don't seem to guarantee items. Is that on purpose?

I always see an item when I use those glyphs.

Post your vault code, could be a different problem.

mumra gives good advice. The behaviour described in the OP sounds strange to me. Post the whole vault and someone can figure out what the problem is if it's an obvious one.

Sorry, I must be having vault test fatigue. I'm seeing the items reliably now.