I’m using both Prefix Field Labels and Prefix Field Names.
One clone is a single one, then there is a repeater containing another clone. I’m assuming you can use a clone in a repeater (pretty sure I’ve seen that in the documentation)?
Also, I’m using other clones throughout the website, but don’t seem to notice any issues like this, so that’s why I was wondering whether this error is unique to it being on the Options Page? (and some ‘mixed up’ errors in the Options Page relate to non-cloned items, too)