I don't know if mine is normal or just doesn't work. In seat position there are two handles on the bit you sit on. To get to bed mode you just pull these and it all flops into a nice bed. Now the issue is how are they supposed to work to get them back from bed to seat position?
Grab the back of the second section and lift (top of seat back in seat position) whilst lifting the front of the seat base slightly. Works for me
I fitted the handle end of a nylon dog lead on the back section of mine. Makes it easy to give it a good hoik to get it back into seat mode.