Please check if the server address specified to JoinRoom matches the address of the room server that was received from a Search method.
After connecting to the Master server and searching for a room by a method such as SearchRoom, when calling JoinRoom to join the found room, if you mistakenly specify the address (a host name or an IP address and a port number) of the master server instead of the room server, it may cause JoinRoom to become irresponsive. (In fact, the failure handler will be executed after about 30 seconds due to a timeout.)