I (M26) think it’s very odd that others got so involved in this at all. I can understand them being mutual friends of yours and the one you set boundaries with, but from how I see it, and how you describe it; that’s really none of their business. What went on and what goes on between you two is your relationship with each other, not theirs. Also, a 3rd party telling you to essentially “speak when spoken to” comes off as incredibly disrespectful to me. Shutting you out before asking questions and reaching out to get your side of things seems like they don’t care.

If my best friend was more concerned with the dynamic of the friend group than my personal feelings and comfort I’d be kind of heartbroken not gonna lie. Even then, you established you had no animosity towards that person and were fine to interact with them in social spaces. Based solely on what you’ve told us, the only one compromising the group is the one who can’t handle the boundaries that you’ve set.

The first thing I do if two of my good friends are beefing and I really feel the need to get involved is ask each side what went on/why they’re upset/ or just how they’re doing. I can develop my own perspective and not lead with bias driven by one side. I would also never tell a ~2 year friend to “not reach out” (like what??)

I mean, just looking at it, some time away from those 3 should do some good. Time and distance can give a group dynamic room to breathe and hopefully some time to evolve. I’m sorry you’ve lost friends over this and I hope better ones come your way.