If the extractor is holding the case as pictured and it took a little effort to slide it under and it held while you were trying to shake it loose it sounds like you either have an ammo problem, a recoil spring problem or your thumb is rubbing the slide. Once you slide the case in and get it fully under the extractor does it take any effort to push it out? You should be able to feel some tension but it won't be a whole lot, if so I would look at something else causing the problem. If you have tension on the case from the extractor and the cases are left facing forward the slide is most likely not making the full travel to the rear to be knocked out by the ejector. Try some different ammo just as a test.