What browser are you using? My kids found the same bug on MS Edge but chrome worked fine for them
Yep don't think this is a browser bug
I was able to replicate the bug on Chrome
It is caused by clicking on a staircase the clicking on the other staircase, queuing system gone wrong.
Sorry about that refresh the game and it should be ok.
Will fix this and other bugs before "version 2" release thanks for beta testing :)