I don't know about how things usually are because my kids aren't in HS yet, but I do know that their school district, during distance learning, has a blanket policy that parents are not allowed to record the teaching sessions. So I wouldn't be too surprised if voice recorders aren't allowed in many schools as well.

It sounds like that policy needs to be broken as thoroughly and consistently as possible, provided that you are in a one-party consent state.

I can't imagine any good reason for that policy other than covering for terrible people.

I'm no lawyer, but if I had to bet, I would assume that the wiretapping laws that would no doubt zealously be applied to such a recording event (if it ruffled the right feathers) wouldn't have an exception for that, as they were written before even speakerphones came into wide use.

Sometimes, breaking the rules is the only way to obtain real evidence. ;)

Who said I didn't get into college? Not every country works like the US, attendance has nothing to do with college admission.