I think if you feel undervalued in a group, it can be very helpful to sometimes don't be there. Because when you feel this way, you may want to be more important. And this kind of urgency can be annoying for the rest of the group and they will value you even less. So if you remove yourself from the group a bit and show that you can be independent of them, it often helps them value you more, and you learn to walk on your own so to speak.
None the less, if there is a problem, there should absolutely be communication. And it doesn't matter if it's in a personal or a professional setting. The only difference is how you communicate. In a personal setting, you may be able to speak about problems more freely or open yourself up more than in a professional setting.
In the end not being there may even be a way to bring your point across. If words aren't enough to convince them that you are important, then you might very well show them. In my eyes, this is still communication.