Just looked at ours and tested on and off.....it might be that the studs on your bolts are projecting too far and stopping you making the final pull back that enables lock on.
If you line up the holes in the ring you can probably pull it back to enable the lock on.
On your last picture, the brozne lifeline part should go into the black plastic housing. Please get this right or somthing horrible might happen. As someone said above you should always check by pulling back.
Enjoy...we were out on Sunday and it was wonderful.
