If every other button works and only the left analog stopped, first check it outside the game. Open joy.cpl in Windows (Win+R → type joy.cpl) and test the stick there. If the axis doesn’t move at all, it’s likely a hardware issue (stick module or internal wiring). If it moves there, then it’s just a game/input setting problem.
If it’s hardware, try blowing compressed air around the base of the stick and rotate it fully a few times sometimes dust causes it to stop registering. If that doesn’t help, the GX150 uses a standard analog module and they do wear out replacement is possible but requires soldering.
If it works in joy.cpl but not in-game check if the game switched input mode (keyboard mode or Steam Input profile changed). Also try unplugging it using a different USB port and avoiding USB hubs.
