Hidden Cisterns - Flexible pipe connectors?

I have just inherited a toilet with a hidden cistern, the soil pipe is fine and connected to the bowl and fixed soil pipe with a flexible connector to allow access behind the toilet,however, the connector between the cistern and the toilet bowl appears to be a standard J connector with a rubber push fit connection to the back of the bowl and become detached - causing a cistern sized flood. Is there a better way of connecting the cistern and the bowl or do I just need to attempt to get a better push fit when pushing the toilet back into position?