I have recently had a really hard landing and bottomed out my fork, this time it was different though, when I went back to do the jump again I noticed that when I changed the rebound setting it wouldn't switch between fast and slow, also the fork is acting weird.
I think Maple hit it on the head. The damper works by restricting (partially or fully) the flow of oil from one chamber to the other. If you have ever seen a french coffee press, where you can open and close the "doors" to the sieve. If you were to press really hard with it closed, you could easily blow those doors off their hinges.
It is quite possible that the damper is blown even if there is no oil leaking.