Using Calendar app on Sierra 10.12.4. While navigating or creating events on calendar events will suddenly get created without intention. Specifically when I have one event highlighted, then click on another day (Single click, not double or drag). Suddenly a new event will be created between the two clicks, then another if I click somewhere else. These are events that I cannot delete, and don't actually exist (Quitting and reopening Calendar makes them disappear. Screen capture of it happening https://giphy.com/gifs/gplgBDZqnzxDO/html5