Shifter slop

Had my Competition Plus marked shifter apart this winter. Put new shims in, cleaned and lubed everything real nice. Now, 1000 miles into summer I find I have quite a bit of "front to back" slop, play, whatever you wanna call it.

I can climb under there and hold the shift levers on the shifter and have a buddy wiggle the shifter front to back. Shift levers don't move but I can see the main "shifter actuator arm" moving in the middle.

Can't figure out what it could be and hope you guys have some input.
It's NOT the model with the stop bolts, and the slop seems to be way less in 4th gear