[OPEN] Non functional Xbox controller buttons

Same here, also tried the settings within Steam to "Disable Steam Input" in the Game Settings, but I at least fixed it at my end!

What I recognised is that there is a Playstation 4 Controller (I didn't really use a Playstation 4 Controller) under Settings > Controller > General Controller Settings + when I connect my Xbox Elite v2 Controller it appears also there, so 2 controllers appeared there.

I may have forgotten that, but I used a Nacon Controller before which came with an Adapter connected to USB, allowing me to play wireless and this Adapter was still connected while I wasn't using it for a year anymore (simply forgot about it ...). Disconnecting the Adapter resulted in the disappearance of the Controller in the Steam Controller Settings and from that onwards it worked for me!

You may also look out into these Settings; if you have 2 Controllers there, you may have this challenge and you can start disconnecting "things" from your USB and see if the other controller disappears (it goes instantly, so no reason to reload the settings page).

*** EDIT ***

Forgot to mention, you will also see the Device in the Device Manager under HID, this should provide a hint on what may be connected and recognised as a Gamecontroller. Obviously and that's what I am sure about, it's a problem when 2 Gamecontroller are connected or better to say, if Windows thinks there are 2 Gamecontrollers.

*** EDIT ***

Hope that may work for one or another...