Please provide the following when creating the Ticket:

Game Version number: Experimental 1.2.0.12 (Steam)
Modded?: No

Issue Description:
In a situation which you enter the Mi-8 Armed into the Back Gunner seat and then try to move to a different seat within the helo WITHOUT exiting it, you will not move to a different seat and instead be stuck in the back gunner seat, this will also prevent you from exiting the vehicle entirely. Unsure if there's a work-around but it seems like respawning is the only option.