Hello wdurnin,
Thank you for reaching out in Apple Support Communities. We recommend to make sure that Calendar is set up properly in iCloud for Windows. Let's ensure that your account is active and turned on for your calendar events. Here's how:
1. On your Windows computer, open iCloud for Windows.
2. To set up Contacts and Calendar, select “Contacts and Calendars,” click Apply, then follow the onscreen instructions to set up Outlook.
3. Note: If you see “Mail, Contacts, and Calendars,” selecting that option also sets up your iCloud Mail account.
4. To set up Mail, sign in to Outlook using your Apple ID email address and an app-specific password. See the Apple Support article Using app-specific passwords.
Following these steps may help and is outlined in this article: Set up iCloud Mail, Contacts, and Calendar in Outlook on your Windows computer - Apple Support
We look forward to hearing back from you with an update.
Kind regards.