I think you're right in thinking it's him not having 'adjusted' to the new surrounds. Perhaps he was confident in the old place in x-ties because he was well desensitised to it, but not desensitised gradually to this place?
If he was taken there, he was nervous in the barn or x-ties but was tied(trapped) there anyway, this may have confirmed to him it's not a nice place by forcing him to stay in the stressful situation. The more 'practice' he's had at that, the more confirmed(strengthened) his attitudes will become. Therefore the harder & longer it will likely be for you to change them.
So I would avoid x-tying him in the barn(I don't personally like the idea anyway) and avoid locking him in the barn at all, until with repetition, he's comfortable just walking in & out of it with you. Once he's comfortable doing that, you can take him in there for gradually longer. Then lock him in there for short periods of time with some yummy food - maybe stay there with him if there are no other horses to begin with. Repeat the processes over & over at each stage until he's confident & blase about it before doing something slightly more difficult for him. Then you can start tying him for short spells. I'd start with the tying on a long, yielding(using a tie ring or such) rope, before gradually shortening it & then moving to x-ties if you wish.