RobArms recommends 3-400 rnds on gas setting 4 for the initial break in. Do you know what setting you were on? Did you check the ejector and gas block screws were tight? Did you properly adjust the barrel bolt 250 in lbs? From the sound of it, Im guessing you have the older trigger. All that takes is a honing stone to the contact points on the trigger to smooth her out and correct the failure to resets.
Even if the rifle does have issues other than break in, you can rest assured Terra (employee at RobArms) will get you taken care of. It would probably help if you contact her directly via email or call the office. This should be your first step.