How to make it so dragons don't destroy blocks??

I run atm10 on my own server. I recently went to the other and got myself a pet dragon. The problem is he breaks blocks, like a lot. I've went into the game config files and turned all dragon block breaking to false for pet, untamed, and even block breaking when a dragon is stuck, but still he continues to break blocks. After each config change, i do restart the server so I'm not sure what else to do. I don't want to make it so all mobs cant break blocks