A couple possibilities...
Ball detent not installed correctly under power wheel
Hole for ball detent in lower action block not drilled in correct location
The power wheel wasn't aligned correctly when the numbering was etched on it, so the etched numbers are now clocked incorrectly in relation to the small divots and the cam on the back of the wheel
Possible, but less likely than the above, the cam and etching on the power wheel are correct but the small divots on the back of the power wheel that engage the ball detent aren't clocked correctly in relation to the cam and etched numbers
Remove the wheel and have a look (make sure the rifle isn't cocked) and it should be easy to determine the issue. My hunch is the wheel wasn't clocked correctly when it was etched, in which case it's an easy fix by getting a replacement wheel from FX.