I have a 335ds and I'm having trouble deploying the end seat on the Jshape couch

[JerseyJerry]

I'm pulling the seat up a d out and it will not lock in. Not only that, but when I pull the strap, up and out, the darn seat back comes catapulting down on my hands. Can somebody tell me what I'm doing wrong before I end up with a cast on my hand.

[DuncanM]

Back strap needs to be clipped into the front strap, hanging on to the strap near the front of the seat cushion pull up and out towards the back of the coach hard until it locks in place.
When we picked ours up, the guy doing the demo couldn't get it to work either to show me how it worked. Figured it out eventually, seems like you are pulling it out a long way before it locks in.

[DuncanM]

Clipping the straps together means that the back is down with the back strap coming over top of the seat back to reach the strap from the front seat cushion. The back can't go anywhere when the straps are clipped together.