Domnio XL - problems with uneven results

[therealbyrnesie]

I've had my Domino XL for less than a year and over the last few months I've started to notice that after use, the mortises end up being slightly off vertically, which causes my joint to be offset by 1/16 or more. I highly doubt it my technique. Is it possible the mechanism that holds the bit in place has become bent?

 

[Birdhunter]

Without seeing the unit, my first guess would be the fence isn’t tight. Do the tenons all line up or are some higher than others?