Creating a Plan and selecting Issue Source as Filter. In the drop down there is a limited number of values displayed. When I type ahead the filter doesnt come up in the drop down. Moreover when I type the complete filter name it doesnt bring that filter back. So in the screenshot below if I enter 'INEX Features for 22.3' it brings up a completely different filter with a different name from a different jira project.
I think the limitation there is that if we have say > 20 items with "22.3" or "INEX" it still wont display the one I'm searching for, Hence why I tried entering the complete search string.
I think you are right (and it is annoying). I would suggest changing the name of the filter (crazy, but it works). Give it a short, but distinct title. A word highly unlikely to be in any (or many) other filter names.