Sometimes your calendar sync may act up and not show all events in either Optix or on your Google/Office365 calendar.
To fix this issue, removing the sync and re-adding it will often give the best results.
1 . Go to the resource that has the calendar that needs resetting.
2. Scroll down to the section where you are able to select the calendar.
3. Select Not Synced from the drop down menu and click Save.
4. Go back into the space and select the correct Calendar again and click Save.
This will prompt the system to re-sync the calendars and should resolve common sync issues. The steps are the same for Office365 however that sync uses a Calendar Email address.