That can be a very individual thing. Some Black people act very little different when they are around White people and are very comfortable in both groups..

It mostly depends on what type of vibes the white person is giving off sometimes.

Also someone may behave differently around a "group" of white people (vs a single white person) and not a certain way in a group of people of the same culture/race as themselves.

But mainly I wanted to point out that most white people don't befriend or really hang out in groups of PoC, so have no idea what we talk about, or how we react, or language used, or attitudes towards each other. That's a cultural immersion thing, and most people (of most races really) don't immerse themselves in other people's cultures unless they get adopted or married into it.