new entries revert to "new event"
Just within the last few days, Calendar has begun consistently misbehaving. I create a new event, assign it to a calendar, fill in information such as time and notes. I close the editing window, the new title displays (I'm using Month View) for just a second, and then it reverts to "New Event," and everything I've entered is lost. Oddly, when I enter all the information a second time, it always seems to stay.
As far as I know, I haven't made any changes to my OS (10.9.5) or to Calendar (7.0), neither via their settings nor any other way. FYI, I'm using iCloud to sync between the calendars on my MBPro and my iPhone (4S, running 7.1.2).
MacBook Pro (13-inch Early 2011), OS X Mavericks (10.9)