Smart oven + meal plan: My spouse bought me one for my birthday (a Tovala) and I have to admit I was skeptical at first but hot diggity damn does it make fresh cooked meals easy. We very rarely order out now and the meals are usually very good (stay away from the burgers though, their bread usually sucks).
That's super weird, I've had like half a dozen Xperias and never encountered this issue. Hope you can get it figured out, they're usually great phones. Sorry I wasn't able to be more helpful. Might be they patch whatever bug may be causing it soon too though, they're usually pretty quick/good about updates.
Try signing out, logging into the web instance of your mail/calendar, dismissing all notifications, then signing back in on your phone. If that doesn't work, clear app data for calendar.
I was looking at this the other day on a slick deals post. Let us know how it is!