Ideas
Same problem here. I’ll tell you how I’ve managed to play.
I have a household with 4 teens and only one of them gets tasks, that’s something I haven’t been able to solve but when they come back, I make sure I switch to another household for a second and go back. This is so that when they go to school next time the game will let me follow them again instead of sending them on their own. You need to do the same thing if you see they’re not going to after school activities, right after they come back from school (or only one of them comes back like in my case), switch to a different household and back. This is how I’ve been able to play, only one of my sims gets task which sucks but the other 3 still attend classes and go to prom and all that so not much of a difference. I hope this helps.