3 door seat not moving on runner

[Razorback_Rob]

Like title says. 3 door dturbo drivers seat isn't moving on left hand runner. Right moves fine. I have a suspicion it's stuck on something (maybe bolts raised and stuck on or maybe a coin has found it's way in. Seat is kinda askew at the moment but still In a position I can use.

Any ideas? Ideally I'd take the seat off the runners and see if there's anything obvious but I don't think ill be able to access the holes necessary to take apart. Anyone else any clue?

[Seb_Ryan]

Could be the bit that links it is snapped?

[Razorback_Rob]

From looks of it it's still connected as the arms from the bar under the seat move the same on both sides just only the right hand one comes loose from the rail.