Moved school, friends ignoring me

I moved sixth form in September and my close friends are still in my old school. I feel like they're ignoring me, I used to call them every week and now i haven't called either of them in 5 (and I know they call each other because they’re both online and listening to the same music etc) we don’t really text and when we do its so dry. My birthday is coming up, and i told them my half term dates, and on of them literally said ‘why?’ Is it not obvious I’m trying to plan something 😭 one of them is going away so I asked when they are going and she gave me a really vague window. Usually for our birthdays we book something but I literally can’t because I don’t know when she’s going, and neither of them have even asked so I feel weird saying ‘oh yk my birthday is coming up guys’ like I’m prompting them. I can’t even ask her when she is going on again because we haven’t texted in a week. They post on instagram them hanging out with their new friends etc, is this just a sign I should move on? It feels so weird because we literally revolved our whole summer around each other and now I feel stupid. Are they waiting for me to contact them? Or is that just wishful thinking