Make sure that in the Steam Controller config (Steam Settings) that your Playstation Configuration Support is deselected (turned off).
Dual Sense works fine for me (Triggers and Rumble) when this is deselected.
Adaptive trigger works for you? I had steam input disabled for the game already (only with that the dualsense buttons prompts are displayed correctly) and then tested to disable PlayStation support, it's the same with only haptic feedback working.
There is another post where other have the same issue with adaptive triggers, any additional setting you have?
