Android Calendar and Outlook Calendar are Different

I deleted the email account on the phone and then added it back in, and on first test everything seems to be working

If I create an event on Outlook web or I create an event on Outlook mobile, it gets added to my Android calendar. If I create an event in the Android calendar, it does NOT get added to Outlook web or Outlook mobile.

Hi @Neil Go 

Thank you for contacting the Microsoft Q&A forum.   

To better understand your situation, I’d like to clarify a few points. When you create a calendar event in Outlook on the web, does it successfully sync to your Outlook app on Android? 

If events created on the web are syncing correctly, it is possible that events created on your Android device are being saved to a different calendar. When creating a new event in Outlook for Android, please tap the calendar dropdown and make sure you select the intended calendar before saving. 

 In addition, aside from the calendar sync issue, is your mailbox in Outlook for Android functioning normally in all other areas? 

In the meantime, you may try the following steps: 

1/ Clear Outlook Mobile cache: 

In my test environment, the steps are: Settings > Apps > App Management > Outlook > Storage Usage  

Note: The exact path may vary slightly depending on your device, but the general steps should be similar.  

2/ Sign out of the affected account in Outlook for Android and sign back in. 

If the issue continues after these steps, you may consider reinstalling the Outlook for Android app to refresh the application environment. 

If I’ve misunderstood any part of your situation, or if you have further questions or updates, please don’t hesitate to reply. 

Thank you for your time, and I look forward to hearing from you soon.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".         

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

It sounds like you're experiencing synchronization issues between your Android Calendar and Outlook Calendar. Here are some steps you can take to troubleshoot and potentially resolve the issue:

1. Re-create the ActiveSync relationship on your mobile device. This can often resolve syncing problems. To do this:
   • Remove the ActiveSync account from your mobile device.
   • Remove the ActiveSync relationship from Outlook Web App by signing in, going to Settings, selecting Options, and then navigating to Phone > Mobile Devices to delete the ActiveSync relationship.
   • Restart your mobile device.
   • Re-add the ActiveSync account on your mobile device.
2. Check for third-party Outlook add-ins that might be interfering with calendar synchronization. If you have any add-ins that manage calendar items, try disabling them temporarily to see if that resolves the issue.
3. Ensure that your mobile device is connected to the internet and that there are no connectivity issues.
4. Check for updates for both the Outlook app and your Android operating system, as updates can sometimes resolve bugs and improve functionality.
5. If the problem persists, consider exporting your calendar data to an Outlook Data File (.pst), deleting the existing .ost file, and allowing the server data to download again. You can then import the .pst file data back into Outlook using the "Do not import duplicates" option.

These steps should help you troubleshoot the synchronization issues between your Android Calendar and Outlook Calendar.