this may or may not help.
I have an 1100gs, one time I adjusted the shifter to fit my boots better
got on bike pulled out of drive way, no gear but 1st was available.
like you described, just felt like the shift was locked up.
went back to garage, re-adjusted, was fine.
so in my opinion it could be as simple as the gear shifter adjustment.
Tilt your head, not the taco. - Pati Jinich
Charter member: T.O. club.