Cld be due to the different environment, some baby cry if it's somewhere unfamiliar to them. My 4mo boy is ok but my nephew had tt same prob when he was 3mo. He would cry so hard every time at my mom's or her in-laws place, so hard to pacify him tt my sis had to keep latching him when she's there. But it got better aft a month as she and hubby tried to go to the parents' hse more often, even leaving a baby pool at my mom's place so tt baby cld look fwd to playing there. Maybe can try leaving baby's fav toy or sth she likes there? But I think this is just a phase as at this age, baby is still learning and adjusting.