Hey there!
Im currently developing a game with Unity and ran across a potential issue with Steam Deck and the 2021 LTS version.
Some time ago, I released a version of my game as a playtest version and built it with a stable version of Unity 2020 LTS and the left joystick controls work fine.
Recently I updated my Unity to 2021 LTS and built a newer version of my game as a demo, but when trying to use the left joystick on the Steam Deck, the game freezes. Note that the left dpad and touchpad are working just fine.
I’m suspecting that there is a difference between Unity 2020 and 2021 LTS that is causing these left thumbstick freezing issues on the Steam Deck.
Happy to provide more info as needed, note that I do not have a Steam Deck Dev kit to debug.