Overview
When I searched for this issue, I could not find anything other than uninstalling game and Steam or using Frontier’s launcher instead of Steam’s. This is a simpler fix.
If your Steam launched Elite: Dangerous is not detecting your HOTAS…
Set up your HOTAS with Windows 10 first. Download drivers and upload firmware if applicable. (This guide does not cover this process.) Make sure the HOTAS appears in your devices list. In your lower left search box, type “device” (without quotes) and “Bluetooth and other devices settings” should show up.
Click on Bluetooth and you will see a list of detected devices
If you see your HOTAS listed, you can open Steam and click on Elite: Dangerous to select it but don’t open the launcher yet.
On the middle right of the screen under the banner, you should see a gear. Clicking on it will show you a menu with with Properties as the last selection which you should click.
In the Properties screen you will see “Steam Input Per-Game Setting (requires restart of game)”. My default was “Use your global Steam Input settings (Xbox/Generic)”.
Click on that and select “Forced Off”
Close the Properties window, run the ED launcher and game and when you go into controls, you should see your HOTAS in your controller list!