Probably the lube in the lens mechanism that transfers the motion of the pins on the camera body to trigger the shutter and diaphragm has gotten stiff. That's what it usually is. The camera does not generate a lot of force in that direction, all from springs. The stiff lube makes it hang up. Easy to fix. Take the back off the lens and clean and regrease.
I checked. It seems the body needs lubrication. That's what it seems to me. But yeah it does seem there is stiffness and I bet if someone were to send it in for a CLA they would be very happy with this camera thereafter!
I love the wilderness and I love my trail cameras, all Fuji's! :) GA645, GW690 III, and the X100 which I think is the best trail camera ever invented (to date).