My ss9 has had some issues in the past year of being uninvited to parties, having less friends, etc. His biomom blames it on other kids. I’m pretty good at asking questions and getting answers and I discovered that actually our kid is being a brat. In the most typical kid fashion. So now we have conversations about how we make and keep friends and good relationships. It’s working but we have a way to go. A lot of parents take their kid being a jerk as a reflection on themselves (which can be true) but in the end, we gotta be resilient and capable of taking criticism.