Whats the diff..........
A court order is signed by the judge, therefore what it states is what you go by. The parenting agreement, if that was incorperated into the court order, it is something you are bound by, until modified.
Not automatic, you need file contempt charges, if the parenting agreement, that is signed by the judge is not being follow as states, only contempt charges can be filed.
You can try to work with your ex in making the agreement stand and both abiding by it, if not, you will have to enforce it by contempt charges or file for a modification. you can by yourself petition the court to modify your parenting agreement or custody itself, with enough documentation to prove there is a change in circumstances that warrents a modification.
JMO, and basically how I understand this whole legal system, but there are bonafide lawyers on this site that can give you legal answers to your question, and tell me if I am unclear in my understanding.
Best of Luck.
Lissa68