Ah, the joined buildings were missing from a list, that took me 5 seconds to fix, thanks. The fountain's compression was too much for it's sprite sheet, that's also sorted. As for the backdrop I'm unsure about. Is it any backdrop in particular? I haven't experienced that issue at all.
I've been tweaking the trains bit by bit with different interactions but yeah, they still get stuck, I think I know why but that's a slightly longer fix.
New vid should be out today where I talked about them quite a bit so stay tuned for that, appreciate the help!