Chromium browsers fire a gamepadconnected event when a button is pressed or an axis is used, Safari seems to only do so when a button is pressed. See: https://developer.mozilla.org/en-US/docs/Web/API/Window/gamepadconnected_event Repro steps: 1) Connect a supported game controller 2) Force kill the Xbox Cloud Gaming PWA and launch it to simulate a fresh start. 3) Move the left joystick. Nothing will happen in the UI. This is what users are attempting to do in the Xbox Cloud Gaming home screen, and this leads them to believe that the service isn't working with their controller since the UI isn't being perturbed. 4) Move the d-pad or perform any digital input (LB/RB, ABXY, etc.). You should now see the UI respond. There seems to be a bug where the Xbox Cloud Gaming home screen doesn't pick up joystick inputs on a fresh start. To users, this feels like the UI isn't responding to controller input. The important thing is having the game controller connected when starting the PWA. In this case, there is no connect event that occurs as part of the plug-in and instead the connection is based on the user input.
<rdar://problem/87464091>
I am experiencing the same issue. The gamepadconnected event is not emitted when a gamepad is already connected to the machine and the stick/axis is moved, but only when a button is pressed. This is different than what stated in the documentation, i.e. "The gamepadconnected event is fired when the browser detects that a gamepad has been connected or the first time a button/axis of the gamepad is used." It properly works on Firefox and Chromium browsers.