Board Thread:In-Editor Help Assistance/@comment-35927883-20191216093227/@comment-9605025-20191216231229

When you say you "added" it, did you add it while editing the template page or did you use the "add more information" button at the bottom of the form that VisualEditor uses to place the template on pages? If the latter, that doesn't edit the template to add the field, all it does is pass it to the template call. The effect is that the page is giving the template a value that the template doesn't do anything with.