I'm trying to breed for a timid ralts with synchronize in Pokemon sun, so I put a female ralts in the nursery along with a timid male pancham with an everstone. However, the nursery lady says that they like to play with other Pokemon rather than each other. They're both in the human-like egg group, so they should be able to breed. Another thing that might be important is that both the ralts and the pancham are newly hatched.