When subscribing to your Teams presence, you will be set as busy on all of your devices when the following presence states are active:
In a call will be active when you are in a Teams call.
In a meeting will be active when you have created a Teams meeting directly in the calendar, in Teams, or you part take in a Teams meeting. The state may also activate when you create a Teams meeting in your Outlook calendar and choose to show as busy.
If you create a regular meeting in you calendar, you will not get this status and your other devices will not show you as busy.
Presenting will be active when you share a screen during a Teams meeting.