In SMART Mirror, AirPlay, Google Cast, Miracast can be enabled / disabled within the app under Settings > Network & Connections.
If you do not want Mirror to run accept connections when the app is not in the foreground, you can turn off the "Floating ID" within the app under Settings > Session Management.
Please let me know if this does not resolve your concern.
In SMART Mirror, AirPlay, Google Cast, Miracast can be enabled / disabled within the app under Settings > Network & Connections.
If you do not want Mirror to run accept connections when the app is not in the foreground, you can turn off the "Floating ID" within the app under Settings > Session Management.
Please let me know if this does not resolve your concern.