Rabbit eating walls

Hi guys,
I hope I posted this in the right section, as I suppose it's an odd quirk
Our bunnies eat the walls, we have a few corners that stick out in the room they live in, and they've always nibbled on them. I was a bit like as we rent but wasn't too bothered as it's fixable.
HOWEVER, they have actually eaten THE WALL and got into the insulation and even nibbled some of that off I'm at my wits end as it's the "outer wall" which means I can't put anything infront of the wall otherwise we get mould! (Already happened). Does anyone elses bun do this?! I was thinking of getting those fences and putting one in the room so they cant get to that wall... but the thing is Amelie can jump so high (she jumps onto the windowsill) she would manage to jump over it.
Help??? Anyone?!?!?
Thanks

Hi, my buns are outside so not had this problem myself, however, other posts on here have recommended putting puppy panels against walls for similar problems. I know you can buy these from Amazon. Hope that helps !

my rabbits do it and its one of the reasons they are moving outside if we ever get a decent spell of warm weather. I can't believe we are halfway through May and it is still too cold.