You did a good thing and got out of your comfort zone and engaged in a friendly manner. However, it takes practice, and you may have given off a “used car salesman” vibe or some other vibe without meaning to. Also, some of your new coworkers could be very introverted or even snobs. You can’t control other people, only yourself. Give it some more practice, but maybe dial it down a few notches. Trust has to be earned in both directions and this can take a long time in some work environments.