I wish I had room for a C&C cage, but unfortunately, this is the largest I really have room for for now.
Knowing the pig that does the burrowing, she probably is just curious (or wants to make my life a pain!). This is like her. She also is the adventurous one when it comes to trying new food, meeting new people, and reminding me it's dinner time.
It can be difficult to stop a pig that's a burrower. If you had a typical C&C, you could use strips of extra coroplast to hold down the edges. That's not an option with this type of cage. If your fleece is larger than the cage bottom, you might be able to roll the edge under with a long, narrow piece of wood inside (like a thin piece of trim) and then hold it down in the corners with something heavy (some people use a small brick). Another option is to actually give the pig a different option for burrowing. Put down extra squares of fleece so the pig can burrow under them and not under the main fleece. There's someone on here that sells some really nice fleece blankets with a built-in pocket for burrowers.
I know with a few foster pigs that were burrowers, I eventually just gave up and went back to a loose bedding. I got tired of fighting it, lol.