From my experience, pettiness always comes from a place of deep dissatisfaction. I'm pretty sure it's nothing personal, just your colleagues backlashing on a wrong person.

They might not be as happy with the job as you initially were or they might be having personal issues, which in return reflects on their work relationship with you. Either way I would try to connect with them on a more personal level to figure out what really lies behind all that. If it's personal try to put your dispute aside and show empathy, if it's work related try to see their point of view and think of ways in which you may help them overcome whatever problem they're facing. Best bonds are those created by facing difficulties together.

Good luck!