OpenTX Radios in Joystick mode not recognized

In games like Liftoff, DCL or DRL Simulator running under Proton either doesn't recognize an OpenTX-based controller or recognizes something but it's output is completely unusable. Interestingly enough the wine joystick settings in the control panel seem to read the joystick without any issues as well as steam input, just in-game it's unusable even with steam input off or on. DRL is using Rewired from the Unity store for control if it helps at all, I'm not sure about the two others. A PS4 controller works flawlessly in these games.

If you need any additional testing / info let me know.

System Information

• GPU: RX 580
• Driver/LLVM version: Mesa 19.2.8
• Kernel version: 5.5.10
• Link to full system information report as Gist: https://gist.github.com/tenten8401/67bee1f73f49febb15873bb4a015c7be
• Proton version: 5.0-5

The issue names no source files, tests, or entry points. Start by reproducing the OpenTX controller behavior in Liftoff, DCL, or DRL under Proton 5.0-5, comparing the Wine control panel and Steam Input results with in-game input. Done means the controller is recognized with usable output, or the incompatibility is narrowed to a documented component.