I've been using the new preview Forms trigger. To be of value, I want to use this in spaces that do not belong to an individual so I am specifying the Form ID of a 'Forms for Excel' that lives in an O365 Group. The ID works in the Flow creation process and pulls back all of the relevant Form fields for use in my Flow BUT, several Form responses later, my Flow has never triggered.
FWIW - I think that Flow functionality for Forms is a huge bonus. Lots of significant business benefits. Great effort getting it this far but please fix!