Help tags don't appear on subform fields

On most of the forms in TVB web GUI we have a Text label, a green question mark, and then the input field.

This works well on the Simulator page, for example, where the green questions marks appear, and when clicked will show the "doc" attributes from code Form classes.

But this does not work on pages with subform, for example on the Region Stimulus left side.

TO be investigated if this is a Form class definition problem, or it is an HTML/JS issue.