Quoted:
#1 will fail to eject sporadically; usually within the first and possibly second rounds. After that it usually functions well. #2 flat out fails to eject on every single round.
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Did you manually cycle rounds through the action before shooting it? How do/did they extract/eject?
If the ejector adjustment doesn't solve your issues fully, you can look at the buffer length/weight and or ammo (low powered?) not allowing the bolt to fully cycle.
Check if your bolt is dragging (possibly on bolt catch or elsewhere) and slowing the action.
What mags? Sporadic issues could be mag related if the mag is dragging the bolt or otherwise interfering with proper ejection. Are you by chance holding the mag when shooting? I have seen several AR9s where a shooter holding the magwell/mag has caused intermittent or consistent ejection issues.