I think this is a design issue - unless the entire user settings interface is redesigned, there is no way to solve the problem of buttons being hidden behind tabs. After all, the device is only so wide, and it is impossible to fit so many buttons.
On my device, the tab is just long enough to leave the gear halfway open, which lets you know there are buttons behind it.
So I wonder if adding explicit arrows when the length is insufficient would make people more aware of the existence of the horizontal slider like this…
