Unfortunately, the effect of eroded community trust seen in many places with ethnic diversity seems to occur even when all the ethnicities share common moral values or even share a religion, but are separated by culture.

My mom has been making new friends in a new community, and they seem to mostly bond over stuff they liked as kids and cooking. She and her newest friend binge-watched old episodes of The Monkees and they trade tricks on how to improve their old recipes, which are basically the same for both of them. That sort of relationship-building is predicated on shared culture throughout life.

An immigrant from, say, China, simply isn't going to have listened to such bands in the 60s or have a family recipe for Shepard's pie. And that is a very real barrier for such a person for relating with someone like my mom.