What are common reasons afci circuits won't work?
This almost always results from mixed of interconnected neutrals. If you have a connection between neutrals of different circuits, or the neutrals are switched, then the current through the GFCI circuitry is unbalanced, causing the trip. 

The other thing to check is that you moved the neutral wires from the neutral bus to the neutral terminals of the breakers. 

To debug this, turn off all of the breakers and disconnect all of the neutrals (mark them to keep track of where they go). Check for continuity between neutrals. If you find any, you’ll need to track down where they are connected. 

If none are connected, turn on a load (e.g. light bulb) on each circuit. Go to each hot and find the neutral that shows some continuity. Make sure these are paired on a breaker.