No queries displayed in Query Monitor

I have the MySQL Query Explorer v1.0 and can connect to the mySQL server. I have the option to select all my databases individually so all good there. However there are no queries displayed at all. This is a live server with about 30 databases. I've tried both 30 second sampling frequency and hitting refresh at the same time as running a query on the database.

Is there some sort of configuration required to get this to work? performance_schema is set to true