Unity PUN Basics Tutorial not working (leaveRoom)

I've been going throught the "PUN Basics Tutorial" and in the Part 4 I've noticed that the "Quit Room" button it's not working. Thinking that could be something I made wrong I've loaded the PunBasics-Tutorial that is included in the Photon Unity Networking folder (downloaded the Assets Store) but the problem is there too.

How can I solve this? What could be the problem? I think that the change of scene has something to do because I've tried to connect and leave in the Launch scene and it works.