I have set up an Edit widget in my Experience Builder app. Before the user selects a feature to edit, the widget displays a title at the top, which is taken from the name I have given the widget. However when the user selects a feature, that title changes to the word "undefined". I can't figure out where it is getting "undefined" from or what to do to fix it. I've tried using both customised settings and the web map settings for the data source, and I've tried changing things in the web map pop-ups and form builder, but none of those make any difference.
Is there something I'm missing or is this a bug?
What it says before anything is selected:

What it says when a polygon has been selected:
