P38A Tailgate swap woes

swapped the lower tailgate last night for a good condition used one. All went pretty straight forward. Lined up lovely. Old latches and internals swapped accross. Back on checked. Worked like a dream. Too good to be true I thought but was working wonderfully. Rear carpet back on. Shut. One last try . Stuck and stuck good. So ended up having to damage the boot carpet taking it off. And now one of the latches is super stiff so the swapped for one of the other tailgate. Seems to work fine until fitted then goes stiff. Cleaned then and oiled. Still stiff and when you shut the upper tailgate it all jams again. What's going on?

Sounds like it's out of alignment on the catches.

Well faffed for 30mins. Catches fine. Centre lock was the issue. Just the upper to change to get rid of the dent and the half working demist screen