i had an "Redundant Qualifier" issue in my code. The severity of this issue was "Warning". I opened the context menu from the lightbulb and changed the severity to "Suggestion". After this i expected the mark in the marker bar to disappear and get a green square in the upper right corner as this issue was the only one in myn code. Instead the mark was still be shown (but without warning in the tooltip). I opened the context menu again and found all entries doubled (but still working):
After changing the severity again to "Hint" and reopen the context menu it was displayed in normal state. Nevertheless the state of the marker bar didn't change. I had to delete the redundant "System." to get the square green and the mark to be removed.