Steps to reproduce:
1. Open any Project with the new Input System Package Installed
2. Navigate to Edit > Project Settings > Input System Package or Open an Input Actions Asset
3. In the Actions section create a New Action with a Button Type
4. Select the default Binding and in the Binding Properties Panel click on the "Listen" button for path
5. Hold down the right mouse button or the middle mouse button and observe the Listener list

Actual results: A named button entry and an empty entry is added to the list

Expected results: A single entry is added or the second entry is named

Reproducible with versions: 1.8.0, 1.14.2

Tested on (OS): Windows 11