Unwanted placeholders everywhere

Hi there,

I have a weird problem on all of my webforms, which seems to have appeared out of nowhere:

All of my text and number fields now have a placeholder in them, which in each case is the same as the title.

This wasn't happening a couple of days ago. The only module I've installed since then is Webform Term Options, which is unlikely to be the cause (de-activating it hasn't made the placeholder issue go away). It sounds similar to the functionality of the module Webform Hints, but this isn't a module I've installed.

Is there anywhere in the UI where one can configure placeholders?