Shifter won’t move….ideas?

Hey all, I’m new here, and I just got a 2003 Sportsman 700.

I’ve done some searching the forum and the web to no avail. I just got it running again, but the shifter won’t move at all.

I’ve taken the cover off behind the shift linkage and checked the gears behind. The lockout (from brake) was rusted in the disengaged position, so I worked it free and put anti-sieze lubricant over it all before reassembling. I’d like to not have to go through the entire transmission removal procedure if I can avoid it.

Not sure if anyone else has had a similar issue, and if so, perhaps, there is a way to get the shifter to move out of Neutral that I’m missing. I’m a motorcycle mechanic, so I’m pretty savvy with this stuff usually, but I just have no knowledge of this machine.

Thank you for any and all advice.