Calendar app wont close! (8.1)

[way_un]

I got the 8.1 (Australian CV) update to my Lumia 520 today. One thing I noticed is, if I open the Calendar and tap the back button, the phone returns to start screen, but if I tap and hold the back button again it shows the Calendar app there as if running (if I tap on that the Calendar opens). To remove it I need to tap on the close button of the window. Has anyone noticed this? Once I've seen two calendars and two instances of the start screen too!

Another thing I noticed is, sometimes the screen freezes for few seconds without responding. (when changing settings with sliders such as show more tiles, wifi) I never noticed this behavior, before the update.
:amaze::amaze::amaze:

 

[aikidaves]

Yes, there are several apps that do this on 8.1, including Calendar, Facebook, Facebook Beta, and even Battery Saver (Battery Saver is fixed in the GDR1 update, though). As for the lag, I've gotten it a few times, usually after not restarting the phone for a week or three, but a soft reset has fixed it each time, so I don't worry about it much. Memory leaks, maybe?