Just in case: Are you sure you selected the Controller Pad tab before adjusting it? Because the UI defaults to the Keyboard tab, and adjusting it there probably wouldn't do anything for you.
Yes, I did. But thanks for the idea.
The one you want to change is Right Stick Sensitivity, not Aim Sensitivity. I guess Aim Sensitivity is only when holding LT for aiming down sights. It's the same sluggish aiming on the Steam Deck and it was really annoying me.
Oh, well I feel silly, I don't know how I missed that. Thank you.
It sounds like if you've turned it up to 10, that the control setting on their end needs to be adjusted. Lots of things like that are broken; like motion blur for example - turning it on or off doesn't matter, it stays on.
Have you tried turning it down? I noticed the Right stick X/Y inversion options were flipped (changing Y option inversed X), so some settings are likely bugged.