I think it could be CAH related, but probably not.    She probably doesn’t want to be at preschool, and if she acts badly you come and pick her up. I would try some behavior modification.

Both of my children are well behaved,  but I stay on top of them with rules and direct consequences for bad behavior,  I have done so since they were toddlers.

There have been times when my kids have not "been acting right" and it is easy to say it is the CAH, but their levels have never shown this to be the case. All kids go through bad stages,  you just need to find a way to work through it,  discuss options with the school.

Good luck to you.