What you were expecting to happen, and what actually happened:
I expect to find shop, boss or deadend after 6 rooms. There are 11 rooms at the bottom before arriving to a deadend
How often does this happen? When did it begin happening?
First time it is happening
Steps to make it happen again
Fight in the underspire
Be prepared to post your in-game Invite Code (as shown on the Settings menu) so that the devs can consult server logs. Underspire maps vary per player, but this isn’t the first report – and it seems to only ever occur along the edges of the grid.
Dead and buried. It’s considered to be working as intended, because the endless corridor doesn’t exceed the guaranteed limit of 6 rooms. In case you are questioning your counting skills, the magic trick was to claim that repeatedly extending the path by another up to 6 rooms actually makes that several individual paths, so everything is just fine.
As much as the community was able to figure out, the bug only happens when a path hugs the border of the map, and it only rarely happens in such a situation. Incidents like these also convinced the community that reporting bugs that harm players is a lost cause, the best you can hope for is not getting ridiculed.