Has anyone else experienced this?
An imp is fortifying an earth tile, and on the other side there is a tunneller. You know it takes 2 digs to destroy an earth tile? If the tunneller does the first dig, and at that exact moment, the imp finishes fortifying, the wall will still be fortified, but it doesn't stop the tunneller digging through it. The tunneller will keep digging and breach the wall as if it was a hero fortified wall. This has happened to me at least twice.
I don't know if this is fixed in KeeperFX, nor do I know if this is the same issue reported here. This is something I've encountered in normal DK. I don't know if this also happens with imps and enemy Keepers.