Hi James,
Yes, I can confirm I enabled pro, then disabled 4.4.6 before visiting /post_type=acf-field-group. I reverted database and ran through again to double check and had exactly the same result.
By using this gist https://gist.github.com/thisislawatts/89f17ab4075638a57657,
adding the mod update.php, visiting /wp-admin/edit.php?post_type=acf-field-group&page=acf-upgrade ***once only***, reverting update.php, and then finally returning to /post_type=acf-field-group I found my fields displayed and usable.
Hope this helps. David
