Track the mouse or keyboard buttons pressed or released

Problem:

My logitech T400 mouse is working but the middle button press is not detected. The middle button just works for scrolling.

Solution:

Before trying to remap the button, you should assure that the middle button click (press or release event) is detected.

Step by step:

1. Use the xev (X Event Tester) command to view events using the X Window System, a framework for creating and managing graphical user interfaces (GUIs), available in Ubuntu.

xev

Optional
You can search for specific lines, for example the ButtonRelease

xev | grep -A2 --line-buffered '^ButtonRelease'

Source:

https://superuser.com/a/462789
https://www.baeldung.com/linux/monitor-device-events