This could happen if the ID of the form changed during the important. Typically, WordPress tries to keep all of the IDs the same, but in some cases they can change.
You might need to re-build it. Happy Forms is actually really easy to customize if you give it a shot.
Yes, it was an empty site. I wiped the site and reinstalled the demo content and the problem still appears.
When I go to pages to add the happyforms form, there’s no add happyforms button. I’ve disabled gutenburg and I’m still not able to add the happyforms form to the page.
Ok, I created a new form and added the new ID to the website it’s working. Thank you for your assistance. Strange that it wasn’t working for the default form.