So for more than 18 months there was a bug in the new form element that meant Gravity forms did not work with Ajax. (Possible more than 2 years…)
This meant we either needed to use the classic element or the shortcode.
I’ve pretty much used the classic element a loads of sites.
With the upgrade from Pro 5.1.5 to Pro 6 the connection to the form is lost and we need to manually go and reattach the form.
I brought this up here but the issue is still present when upgrading from Pro 5 to Pro 6.0.7