When a misfeed occurs, the old brass usually fails to eject and gets stuck behind the next round,
If a case is failing to eject, there may be some issue with the extractor. The first thing to do is NOT to start filing or sanding on the magazine lips because if they are not the problem, they soon will be. If you do not want to take it to a gunsmith but investigate the cause yourself. Try to slip a fired case under the extractor and get the empty case back into the chamber. Put one round into the affected magazine, insert it into the gun. Pull back slowly on the slide and watch what happens in an attempt to see why the empty case is not being extracted and thrown clear by the ejector. Test, experiment, but cut no metal until you are very sure what is causing the problem. Nevertheless, it sounds like more of an ejection problem than a magazine problem.
Examine both the extractor and its spring (.22's are very dirty, things get sticky very quickly), and the ejector.
One other thing to try, is a new box of cartridges...I have an old brick of .22's that fire, but do not have the required power/force for the empties to clear the chamber of my Buckmark.