The first year of highschool is coming to an end. I have a friend group of five (gonna call my friends Z, F, W and M) and even tho there aren't too many things that we're sharing an interest in, it's still a pretty solid one. I was pretty happy to settle with friends, especially with my sensitivity with all previous friendship stuff.
Two weeks ago or so, I was coming back home, talking with Z. We don't come back together too often (all of us live pretty much in different towns or smth). We talk about many different stuff and all, and once he said smth along the lines of "Don't you feel that F is acting a little weird lately?" He gave some good examples of it, how the constant jokes get really boring and are repetitive, how it started after he began animating, and probably some other stuff I can't word out here (I just don't know how, maybe wait for an update or smth). But I generally agreed with all that, tho I prefer to rather stay neutral and just decided to say smth like "well, what can you do?"
It wouldn't be too much of a concern if it didn't happen from the other side. Last week, I was going to the locker room with F, and we casually passed Z. F said "hi" to him, and Z didn't really pay that much attention and just walked where he was walking - back to class. And F just told me smth similar, along the lines of "Don't you think Z is acting a little weird lately?" I brushed it off similarly (I think), but I couldn't shake off the thoughts of these situations. Not only that, I kind of feel like the mood of Z kind of disconnecting from the friend group got to me, and I started responding less to F's jokes (maybe those repetitive jokes got to me too).
I didn't know if I should post it right away - someone might think "it's just 2 out of 4" but like, it might trigger something more, something bigger. It's already pretty logical (and visible) that depending on who are we around changes the way we act in a group (no difference in my situation), but I'm kind of scared it might be the beginning of the end of this friendship. I'd like to think I'm worrying in advance and just overthinking it, after all, friendships come to an end. But I couldn't really find one best friend to share all ups and downs with, and even if it's not the opportunity for it, I want this friendship to last more.
(Also, I never had anyone in any of my friendgroup to tell me that one of the others is 'acting weird' or anything like that. At least not in this serious way - that's I felt they told me, and I doubt I'm wrong about this)