Just fixed it.
Found a thread on the other place:
https://old.reddit.com/r/Diablo/comments/11tx1qg/fyi_d4_works_through_steam_link/
Pasting here:
How To:
Add to Steam
- Open Steam
- Go to Library
- Click "Add Game" at the bottom left
- Click "Add a Non-Steam Game"
- Click "Browse..."
- Navigate to your Diablo 4 installation folder (.../Diablo IV)
- Select "Diablo IV.exe" (.exe extension might be hidden by default, so it will only show "Diablo IV")
- Click Open
- Click "Add Selected Programs"
- Minimize Steam
Configure Battle.Net
- Open Battle.Net App
- Click on "Battle.Net Menu" (Blue swirly Icon at the top left)
- Click "Settings"
- Under "On Game Launch" select "Exit Battle.Net completely"
- Under "When Clicking X (Close Window)", select "Exit Battle.Net Completely"
- Click "Done"
- Close Battle.net App (X top right corner), making sure the app is not minimized, but completely closed. This is imperative, or Steam won't take control of the game for controller support!
To Play
- Open Steam
- Click the Shortcut you created in Steam Library, "Diablo IV". It will launch the Battle.Net App, THIS IS NORMAL.
- Once the App is open, click the Play button on the bottom left.
- If you have a mouse, use it
- If you have a touch screen, tap it
- If you have a controller, press and hold the "select" button (on Xbox controller; I don't know what it is on the other controllers, it's the one that opens the blue stream menu at the bottom) and change to mouse mode (Controller/mouse symbol) and click play
- The game will launch and the Battle.net app will close. Once you see the Blue notifications at the bottom saying "... Controller configuration loaded", you'll know that everything worked and Steam hooked successfully into the game for controller support.