It isn't the kind of experience that we want you to have, matt82au.
If you've already established the connection yet, the same thing happens, I'd recommend reaching out to our Phone Support team. An agent can do a screen-share with you and verify what causes the error.
You can contact them by clicking the ? Help icon and then continue with the on-screen instructions to get in touch with our support.
Once the error has resolved, you can save this link as your references when invoicing with Google Calendar: Invoice with Google Calendar FAQs.
I'll be around if ever you need help. Keep safe!
