took the 4 speed to the track

Any of you guys have any issues with the Liberty shifted trans wanting to pop out of gear? I'm running a 18 spline that is freshly rebuilt with new gears etc, pro shifted 1-2 and faceplated 3-4 recently. It shifts great and no vibration. I'm using a Hurst Vertigate and the stops are set so it's getting in gear, it just wants to pop out when you let off the gas/decelerate.

Any thoughts or suggestions appreciated. Thanks!