Yet I haven't checked the checkbox to open Cookie (v6.3) at login:

I've had to completely uninstall Cookie 6 because it was constantly displaying a popup requesting access to the folder Application Support. Even after allowing access several times, the popup would re-appear incessantly. It's a real nuisance and difficult to get rid of because Cookie 6 doesn't appear in Force Quit. If I remember correctly, this has happened since I completely uninstalled Firefox. I hope a fix will soon be made available.