We chose the option of both driver and passenger swivel seats when we ordered our 3011 and we love them.
They're getting easier to maneuver every time we turn them around. To lock the driver seat in place we start by getting it turned around to the front then slide it at an angle along the track to lock it into the final spot. Sometimes I have to give a bit of force and get sort of a "running start" to lock it into place.
If you slide them along the track slowly they don't go far enough forward to lock in the proper position and stay locked. I put a bit of momentum into it when I move it back to the final lock position.
The other thing may be that the release pin or handle are sticking in the unlocked position and don't engage when the seat is moved back into place. Other than that I can't think of what would cause it to not lock.
2015 Forest River Forester 3011 DS - 2007 Dodge Durango Toad