Exact same thing happened to me ..
I knew from the start that the SMP chronos were bad for this but here is what I did ..
I have 2 SMP chronos , one I bought for my brother who could care less about the watch so I asked him to let me see it for a bit , well I took the case back off of mine and pulled the crown out by pressing the little button where the arrow is and then just pulled the crown & stem out , so now I did the same to his and just switched the two , his crown & stem was actually about 2 millimeters longer than mine which I thought was weird but I installed it in my watch and now it works fine and actually screws in allot farther than before ...
So I put my old crown stem back in his watch cuz he could care less if it screwed down or not and to my surprise it worked properly in his watch too ??
So , I would try just pulling the crown & stem out and cleaning the threads on it and then reinsert it and see if it works , not sure on that but try and find another crown & stem and switch the two , I am also wondering if the Gen crown & stem would work with the rep tube , maybe The Zigmeister could step in here ??
Zed