You can categorize "humility and willingness to possibly be perceived as dumb" as non-communication skills, but in my mind they are:

A) the most important indicators of likely success on the team B) very correlated with comfort in speaking

If I can't get you to talk at all when you're uncomfortable, you're unlikely to tell me you don't understand in the often uncomfortable iterating on a feature process.

It's possible to be gregarious AND be unable to ever admit that you lack critical information, which is why interviews, for me, are mostly about asking questions until we get to the point you don't know/don't understand, and see how you work with me from there on.

What a lot of people who get stressed about interviews don't realize, though, is that WHERE PRECISELY you reach your limits is unimportant. It's that you engage thoughtfully, without getting overly defensive, and don't bullshit. Not about whether you got the right answer at any given spot.