Re: My gelding has become a real pain to ride.
In addition to Tommy's questions, I'd also consider that it could be pain/discomfort related - eg back, tack, teeth, neck, etc.
But assuming he's been fine for the last year & it's only the recent move that's changed him, it could well be this. If it's very recent, part of it could be nervousness at being in a different environment. It could also be to do with his associations of the place & 'work' based on his old regime here. Horses learn by association & they can be very strong. Depending on how much 'bad' experience he got previously, how much the behaviour was reinforced, purposefully or otherwise, it may not take long to get him back on track, or it could be an issue for some time.
I'd go right back to the basics & get him going well there before asking for gradually more.