Resetting a setting to its default in your settings hub used to be a one-way door. The setting disappeared from the screen as expected, but the key stayed quietly claimed underneath, so setting it again was refused — “a setting with key … already exists” — for a setting the page was showing as unset. There was no way back to it from anywhere in the product.
Resetting now clears the setting properly. The stored value is removed, the setting falls back to its default, and you can set it again immediately, to the same value or a different one.
Any setting that was already stuck this way has been freed as part of this change — you do not need to do anything, and nothing you had set has been altered. Only settings you had explicitly reset were affected.
One thing worth knowing: a reset is now genuinely a clear. The previous value is not kept anywhere, so if you reset a setting you had tuned, note the value first if you might want it back.
Support staff clearing a setting on your behalf from their console have always worked this way, so both routes now behave identically — a setting cleared from either place is simply unset.