Does it eject if you "force the gun open when at is maximum ? With any new gun there can be a little working in that was not obvious in the factory when those who check them when finished can be a little heavy handed in the opening and so throwing the gun open as opposed to opening it may well have had the ejectors working .
There are two things which I would look at first , had the gun come to my shop , 1 dried up oil causing stiffness in the trippers . 2 that there is some drag/roughness on the ejector kicker/trippers in the forend so they are not camming cleanly , that may only just need to be polished to cure .
