Is it on any kind of an incline? I'd start it and let it roll, very slowly, while trying to move the shift lever. Did you try moving it back into 4X4 mode first, and then back into 2X? Have you tried moving the transmission gear shift lever through the gears before retrying the transfer case lever?
I've heard of this, but have never experienced it. Usually it's hard to move it at all when it 'decides' not to cooperate.
Jay & Peggy Monroe with Dolly
Can't take it with you - don't plan on leaving any behind
2016 Newmar London Aire 4553, Spartan chassis
Wrangler Unlimited toad