Missing administrative calendar

I’m having the same problem. I just upgraded to the latest version. I use the Striking theme. I can’t see the administrative calendar. If I toggle week/month, the calendar appears, but if I try to scroll through, it displays subsequent months, but the month name doesn’t change. E.g. I scrolled to what should be March, and it apparently is, but it says February. I was able to add an event, but when I was done, the event displays on a different day.

On the front end that the public sees, it looks ok.