@MCaS 

The Arrive Home and Leave Home are the preset shortcuts, it is a one-time operation that helps you control Tapo smart device with one tap. For example, if you want to turn all the lights on and the camera privacy mode when you arrive home, configure the device settings in the Arrive Home shortcut, then you can control those devices easily without configuring them one by one.
 

The Action Become Silent and Ring of the H100 are also one-time operations. User can create a shortcut to trigger the H100 to Become Silent when something triggers the hub to ring, with this shortcut, you can stop the ringing immediately. 

The state of the Tapo device will change according to the settings set by the user or by the manual control. In your case, the Become Silent and Ring action will only change the current state of the hub when you operate it. The ring will be triggered again if the detection of the T100.

In your case, you can create a shortcut to enable/disable the automation (trigger ringing when the sensor is open). 

Tapo APP-->Smart -->Add a new Shortcut -->Add Action -->Enable/Disable Automation.

Learn more about Tapo Smart Action here: How to create Smart Action (automation or a shortcut) of my Tapo devices