We have issues with access to some shared mailboxes reported - this has been raised with Microsoft and we are waiting for a fix. We'll update as soon as we know more.
We are still seeing issues with OWA and shared calendars, if you are experiencing this issue still please contact the service desk.
No incidents reported
We are seeing reports of the 'Join' button missing from Outlook web calendar for Teams Calls - the work around is to join an event from the calendar tab on the Teams App.
The teams join button issue appears to now be resolved.