Is the fold not going all the way round because one of your chain stays is catching on the frame? Is the rear end that far out?
I must admit, it looks all kind of wrong to me in the picture. The tyre is what should be butting up against the seat tube (and the main frame tube when fully folded), yet yours looks like the mudguard would hit the seat tube first. They haven't fiddled with the brakes and put the mudguard on the wrong side of the brace have they?
The other possibility - however slim - is that you're not doing it in the right order. Though if it worked before the conversion, this seems unlikely.
However, for the benefit of removing all doubt, when folding you should fold the main hinges from back to front.
- Release the rear wheel and tuck it under.
- Undo the frame main hinge and swing the front end around, tucking the catch onto the drive side stay. (NB this is when the rear wheel moves into its correct position, if you put the seat down before doing this, then it won't fully fold.)
- Undo the handlebar and swing this into position.
- Finally, put the seat down and this locks everything in place.
If you try and put the seat down before completing everything else, you'll find that the rear wheel hasn't tucked up fully.
When putting it up, it's almost the opposite - except I start with the handlebars, then the seat post, then the main frame hinge, then the rear wheel.
This isn't my bike, but this is where the wheel should be when fully folded.