Can't exit floor 3

The exit from floor 3 seems to be broken in the latest build. Moving onto the exit tile pops up the message asking whether you want to challenge the boss, regardless of whether you've already beaten the explorer and/or done her body swap.

Pressing ; to avoid the fight tells you that you need the key to progress, but the key never appears in chests or the shopkeeper's inventory. The message still appears if you add the key to your own inventory via the debug menu.