Recently a dedicated rabbit rescuing customer of ours has had to buy floors to secure no escapees when he goes away and leaves someone in charge.
This issue is new and applies to a couple of rabbits who are intent on digging which has led to an escapee on one occasion (no loss of bunny though).
My experience has been luckier - they just don't dig and when they once did they helpfully filled it in again after a couple of weeks! I know another customer who had this very same thing happen recently and it is amazing. As logical creatures we think a dig is meant to be a route out but with rabbits it is not always the case.
In the early days we had a customer whose newly rescued bunnies immediately dug inside their run. Instead of flooring the run we place 3 x standard tunnels in a row at the back of her border where the soil was looser. The rabbits dug one way and piled it up and the other direction the next day! They also left the lawn alone.
Clear digs, filled trays, planters can help but if your rabbit seeks the ground only then maybe an area you are willing for them to dig in could be the answer. I would certainly like to try this out but my relaxed buns are not giving me the problem just now.
So if anyone can help I would love to hear from you. Solutions and ideas to try for persistent digging - all lateral thinking on the topic will be very welcome!