I agree you should try adding an extra lock on each side to see if that helps.

I have a big Mojave female, she's an absolute doll, but she will try on a daily basis to push her enclosure open. If I forget to latch one side, she'll be shoving on it as hard as she can within 15 minutes.

However, if her cage is completely secure, she'll push for a little bit, then she gives up and is content to stay inside.

Gale