Hello RobertBurnsOB,
Make sure you're looking all all events in the Calendar app on your Mac. It sounds like the Calendar is checked, according to your post.
Do these events appear on Google's website when you sign in and check the Calendar there? That will help us to isolate this further.
If you're using a Google Calendar and they show up on the Google website, then you could remove it and add it back again: Add or delete calendar accounts on Mac
Remove an account
If you no longer want to use an account in any app, including Calendar, you can remove the account.
Note: If you use iCloud Keychain, and you remove an account (other than your primary iCloud account), you’re asked whether to remove the account from your other Mac computers that use iCloud Keychain, or just turn off all the account features on this Mac.
- Choose Calendar > Accounts, select the account you want to remove, then deselect the Calendar checkbox.
Then add it back with these related steps:
Add an account
Choose Calendar > Add Account, select the account type, then follow the onscreen instructions.
For information about adding an iCloud account, see Set up iCloud on your Mac. For information about adding other accounts, see Add an account.
Set up your iOS devices to use the same account, so that your calendars stay up to date across all those devices and your Apple Watch. For more information, see the “Get started” section of the user guide for iPhone, iPad, or iPod touch. For a device that doesn’t use the latest iOS version, get the user guide from the Apple Support manuals website.
Each account you add is listed separately in the sidebar. If the sidebar isn’t showing, choose View > Show Calendar List or click Calendars in the toolbar.
In case it persists, are you using a VPN or security software on either device? As these may cause connection issues: Check VPN (Virtual Private Network) and third-party software to help resolve network connectivity issues - Apple Support
Hoping to hear how it goes.
Take care!
