You thought that your spouse was reasonable while you were married, but as soon as you divorced and your custody plan was finalized, he became very strict. He wanted you to have your child dropped off or picked up exactly on time.
Interestingly enough, he didn't stick to those same guidelines. Once, he decided to take your child out of town for a few days. He got back a day late, leaving you panicked about where they had gone. He acted like it was no big deal, claiming that his vehicle had broken down.
Another time, you went to pick up your child at their school, but the door monitor told you that your child had left with your ex-spouse after school. It was your custody day, so you had no idea where they were going. You called him, and he didn't answer. Later, he showed up at your house with your daughter. He claimed he just wanted to take her on a surprise trip for ice cream, but he hadn't bothered to ask.
These situations are unfair and potentially dangerous. Interfering with your custody time is a violation of the court order. On top of that, if you can't get in touch or aren't being updated on where your child is, it could cause you a lot of stress or even mean that the police need to get involved.
Know that you have options if this kind of situation happens frequently. You can talk to your attorney, and they will give you more information about modifying your custody plan or asking the court to find your ex in contempt.