Can’t follow teen sims to highschool

I have this issue now too! Last week when I played I could go to the school but the school event timer looked like a holiday so it was difficult to complete. A few days ago my teen didn’t get the pop up for me to join but I could still send him alone (I couldn’t choose for him to work hard or anything though and it said he was still at school even when the day ended). And today it just says day off permanently! I can’t even send him to school at all!!