Hi, John. I am an independent advisor, trying to help other users in the Community with my experience in Microsoft products. Please note that I am a user like you and don't work directly for Microsoft.
According to the article on https://support.microsoft.com/office/46ef12a4-0aaf-45ae-91a8-b3315d69f64d
"Your Teams calendar shows your non-Teams appointments because it is synced with your Exchange and Outlook calendars. This means that any events you create or join on those platforms will also appear in Teams. This is useful for keeping track of your schedule and avoiding conflicts.
However, if you want to change this to Teams-only appointments on the Teams calendar, you can do so by following these steps:
Open Microsoft Teams.
Select Settings and more next to your profile picture.
Select Settings.
Under General, go to Application.
Uncheck the box that says Show events from Outlook in my calendar.
Click Save.
This will hide your non-Teams appointments from your Teams calendar, but they will still be visible in your Exchange and Outlook calendars. You can also toggle this option on or off anytime you want."
I hope this helps you. Let me know if this contradicts what you need. I remain helpful in answering any more of your questions.
Warm Regards
Femi