Unity XR disables mouse and keyboard input detection?,Unity XR disables mouse and keyboard input?

I’ve been following along with the course https://learn.unity.com/course/create-with-vr.
Now I’d like to have a fall-back camera that I can control with mouse and keyboard whenever a VR headset is not available.

However, I cannot detect any input on that camera:

if (Input.GetMouseButton(0)) { Debug.Log(“Pressed left click.”); }
When I put that inside the Update() of a script attached to a camera which is active and in the scene, nothing happens when I press the mouse button. (Putting a breakpoint inside the Update() hits the breakpoint, so I’m sure it’s the input part.)

Similar for any keyboard presses.

Does anyone know what could be preventing the input from being detected?

Do you use new or old Input in settings? In your code here you use the old way.
Also what Unity version do you use?