Anyone have a solve for Outlook 365 Calendar creating duplicate appointments when syncing with iCloud?

Hello JayElVee1,

We understand you have issues using iCloud for Windows with Outlook. We'll do our best to assist with this.

For this issue, we'd recommend using these related steps: If your iCloud Contacts, Calendars, or Reminders won’t sync - Apple Support

Microsoft Windows 

After each step, check your contacts, calendars, or reminders.

Refresh Outlook

Click Refresh  in Outlook.

Turn off iCloud Contacts and Calendar, then turn it back on

1. Open iCloud for Windows.

2. Deselect Mail, Contacts, and Calendars, then click Apply.

3. Wait a few seconds, select Mail, Contacts, and Calendars, then click Apply.

4. Open Outlook.

Make sure the iCloud Outlook Add-in is active

In Outlook 2010 and later:

1. Click the File menu.

2. Click Options in the left panel.

3. Click Add-Ins in the left panel of the Outlook Options window.

4. Look at the list of add-ins in the Active Application Add-Ins section.

5. Select the iCloud Outlook Add-in.

Learn how to manage Add-ins with Microsoft Outlook.

Check your default account in Outlook

In Outlook 2010 and later:

1. Click the File menu.

2. Select Info > Account Settings > Data Files. 

3. If iCloud is the default account in the Comments column, select a different account, and click Set as Default.

Restart your computer

After you restart your computer, check if you fixed the issue.

In case the issue persists, what happens when you create a Calendar event using the iCloud website? Does it cause duplicates on your PC? Log in here to check: Sign in to iCloud

Hoping to hear how it goes, take care.