I play Lost Ark on GFN as one of my primary games and it heavily requires the use of mouse movement for inventory management and menu selections.
When Lost Ark launched in 2022 you could play it on GFN and you could use the right joystick to move the mouse in game and the mouse cursor on screen would follow the movement.
However in April 2024 there was a GFN patch that made it so that mouse movement still is usable by the right joystick but the cursor no longer follows in game and the movement is invisible.
The only way to get the mouse to move is if you put GFN in KBM mode by holding start then you can use the joystick and the mouse will move.
This issue is not specific to Lost Ark it affects every game that allows mouse movement.