I got a reply from Gravity and it worked by disabling the legacy markup in the test form:
The form showing on the URLs provided are currently using legacy markup. As a first step, please try disabling legacy markup for the form by unticking the setting at Form → Settings → Form Options → Enable legacy markup . This will cause the form to be styled with a newer theme. After doing so, please test again to see whether the spinner is rendered.
Regarding legacy markup, please also note from documentation About Legacy Markup:
Legacy markup is scheduled to be removed from Gravity Forms with the release ofGravity Forms 3.1.When deprecated, the forms will default to standard markup, operating as if the legacy mode setting has been disabled. This transition may introduce issues if your site has existing custom code that depends on the legacy markup structure.
We don’t have a firm timeline for version 3.1 yet. You can reference the Gravity Forms Changelog for our historical release dates which should help project some idea for when 3.1 may land.
However, this only fixed the form in a test page I had, not the other forms. I thought it had to do with Beaver builder but disabled the plugin and the forms couldn’t even be submitted.
Well, it seems that Cache shouldn’t be enabled on the pages with forms. That’s unfortunate because in our case, those pages are the ones we need to be faster.