[2.0.76] steam controller's back buttons not detected

[JustATempest]

I’m playing Factorio: Space Age on a Windows PC, with no mods enabled.
I’m using Valve’s new Steam Controller. I expected to be able to switch to the Steam Deck bindings so that the rear buttons — L4, R4, L5, and R5 — would be detected natively by the game.

Instead, these buttons are not detected as separate inputs. Steam Input appears to try mapping them to standard XInput buttons instead, so Factorio does not see them as distinct Steam Deck-style buttons.

I do not have any other controller input/remapping software running.

I have tested the following:

- Steam Input enabled, with back buttons enabled
- Steam Input enabled, with back buttons disabled
- Steam Input disabled entirely

The behavior appears to be the same: the rear buttons are still not detected natively as L4/R4/L5/R5.

Since Factorio already supports Steam Deck bindings natively, I’m not sure why the equivalent rear buttons on the Steam Controller are not detected the same way.

I’ve also opened a bug report with Steam, because I’m not sure whether this is an issue with the controller/Steam Input itself or with Factorio’s controller binding implementation.

A link to the steam bug report can be found here. https://steamcommunity.com/app/4165870/ ... 113085535/