Shifter Popping Up

Hello all,
My shifter is popping up past it's usual travel when upshifting only. Not popping out of gear. Just the shifter coming back to far then snapping back. I heard it could be a spring. Can't find a whole lot of info on it. If I shift methodically it doesn't happen. Just when shifting aggressively. Again, not popping out of gear, just the shifter coming back too far.

1990 XL883/1200

Any and all info appreciated.

Thanks