Stuck Collet Nut

I have had my XCarve Pro about 6 months.

Tonight I got my collet nut stuck. I noticed the last few nights it seemed to feel like some grit was in the threads or the the threads were galled. I looked and cleaned everything good. I did not see any thread problems. On my 4th or 5th bit change tonight, I was not able to get the collet off. It will not go in either direction. Stuck tight.

Anybody else have this issue?