@Chrisuk74: Please can you try swiping from the top of the screen to the bottom, then again to enlarge the Quick Panel, and make sure that Sync is highlighted here. While you're here, make sure that Wi-Fi or Mobile Data is active, as this will be required to sync successfully. Now, open the Calendar app > Tap the 3 lines in the top left > Tap on your Exchange account and make sure that the relevant options are selected > Tap 'Sync Now' at the bottom of the screen. If the problem persists, head to Settings > Apps > Calendar > Storage > Clear Cache, then restart the phone.
