Additional features, settings, or issues not covered by specific Microsoft Teams categories
Hi Ali Forrester,
From my experience, it might be the Microsoft Teams web client (https://teams.microsoft.com/) from your web browser in Windows 10 system notification.
See the following image, these notifications came from teams.microsoft.com in Microsoft Edge browser:
In this situation, you can go to Teams web client (https://teams.microsoft.com/), click the lock icon in the address bar, then you can turn off the notification from Microsoft Teams.
If you're in the another situation, please kindly share us a screenshot of the desktop notification from Teams in your environment, so that we can make a further analysis and share better solutions to your.
Regards,
SD