Please submit a support ticket here https://www.advancedcustomfields.com/contact/
This is a block editor issue. More than likely the page template setting is not being sent during the ajax request used to refresh the field groups.
Also, out of curiosity, do the field groups appear if you change the template selection and then save the page? Do the field groups appear when the page reloads? Yay or nay, you should include this information when you submit the support ticket.
