I have absolutely no advice for this but I do want to say this is exactly what my husband went through with his ex.

I’m no expert but if you have joint legal her withholding any medical documents/education documents can most definitely be a case for contempt of court. Same with not regarding you on decisions for her education/programs.

Request EVERYTHING in email/coparenting app. The court will always need solid evidence. Word of mouth won’t work.

My husband’s ex definitely sees my husband as not a parent but to be quite honest bully your way into the decisions. We created a fake Instagram/Facebook because the ex wouldn’t tell us if the daughter would do extracurriculars and all parents are allowed to go and made it seem to the child like we didn’t want to go. She was pissed when we showed up.

Also stop communicating with her whenever you have custody. If she doesn’t do it with you don’t bother on your time.