No it wasn't. Not even close. There was nothing in the Confederate Constitution that prevented any state from seceding. If you say otherwise cite the clause and post it here for us to see. There were some traitors to their states in the South who sided with the federal government. That's true.
“There was nothing in the Confederate Constitution that prevented any state from seceding.”
There was however something in the Confederate Constitution to prevent states abolishing slavery, they knew what was important to them.