Cannot alter #description_display on a subform for a new node

Hi, I'm looking for some guidance here. I am using a form_alter to alter a single field inside a paragraph. When I use:
...['subform']['#description_display'] = 'before' it is ONLY honored on an existing node edit form, but not for a new node edit form. I have confirmed that $description_display is set for the field on the new node form, it is just not honoring the setting. Any help is appreciated. Thanks.