Runner3 (516130) Steam Input (Steam Virtual Gamepad) does not work

Compatibility Report

• Name of the game with compatibility issues: Runner3
• Steam AppID of the game: 516130

System Information

• GPU: RX 580
• Driver/LLVM version: 4.5 Mesa 18.3.1
• Kernel version: 4.19.0-1-amd64
• Link to full system information report as Gist: https://gist.github.com/BeackerXII/a6b9fc48876cff320a15aa55bbaceb15
• Proton version: 3.16-6 Beta

I confirm:

• that I haven't found an existing compatibility report for this game.
• that I have checked whether there are updates for my system available.

steam-516130.log

Symptoms

Runner3 does not pick up inputs from controllers for which Steam Input is enabled. This means only a subset of controllers supported by Steam can be used to play the game (such as the Xbox One S controller with GUID 030000005e040000ea02000001030000)

Reproduction

I will be using the aforementioned Xbox One S controller to reproduce the issue, referring to it as "controller".

1. Connect the controller.
2. Force off Steam Input for Runner3.
3. Launch Runner3.
4. Locate the Enter key prompt on the screen.
5. Press the A button on the controller.
6. Verify the Enter key prompt has changed into an A button prompt.
7. Quit Runner3.
   Log starts here:
8. Enable Xbox Controller support in Steam Big Picture.
9. Enable Steam Input global rules for Runner3.
10. Launch Runner3.
11. Locate the Enter key prompt on the screen.
12. Press the A button on the controller.
13. Verify the Enter key prompt has NOT changed into an A button prompt.

Begin by reproducing the Xbox One S controller case using the listed steps and inspect the attached steam-516130.log. Done means Runner3 accepts controller input and changes the Enter prompt to the A prompt when Steam Input is enabled.