Hi,

We have outlook 2013 what is connected in Office 365. Some users use calendar on overlay mode. Sometimes when open calendar view and shared calendars is syncing outlook choice shared calendar as default (not user calendar). 

I can reproduce this:

1. Open calendar view.

2. Choice my calendar and some other calendars (week view) and overlay all.

3. Shutdown outlook client and wait outlook process disappears.

4. Open outlook client and go calendar view (calenders syncing)

5. Some shared calendar is choiced as default.

After sync if i switch back to mail view and back to calendar its shows my calendar as default (what is correct). If i restart outlook then shared calendar appears again as default.

Outlook is supposed to remember the last calendar(s) selected... if the last calendar viewed was the shared calendar, that's what you'll see on restart.

Its doesn't work like this when all calendars is in overlay view. If i choice some shared calendar and go to email view and back to calendar view. My calendar is selected. If i close outlook and open calendar view then some shared calendar is selected as default. Sometimes users calls and ask why they can make appoitments and need tell to change to own calendar.