Chubster rips the smart feeder door off the other cat's feeder and eats all her prescription food

Greedy cat has figured out how to rip the door off the feeder even with the side shields on. Does anyone have a recommendation to stop him from being able to do it? I've thought about using super glue but not sure if that will ruin anything.

Even a recommendation for a better feeder that's more difficult to break into would be appreciated.

Thank you!