Gravity Forms Message Sent Confirmation Message No Longer Appearing

Support
#1

Hi there - Last week we updated Cornerstone to Version 7.8.9. (I don’t recall if there was a theme update too; if there was, we would have done that as well.) Our Theme X is Version: 10.8.9

After applying the update, we noticed that the confirmation message Gravity Forms usually displays after the form is sent stopped appearing.

We tried troubleshooting it without success.

Yes, we know you don’t recommend using a Gravity form under tabbed content. However, the question is: what was contained in that Cornerstone update that caused the confirmation message to stop appearing?

I’ll share the URL to a product page, so you can test it.

Thanks
Tim

#2

Hey Tim,

Based on the codebase analysis and official release notes for Cornerstone Version 7.8.9 and Theme X Version 10.8.9 (released on June 1, 2026), here is what was contained in those updates that directly affected Gravity Forms’ AJAX behavior under tabbed content:

Before I continue, please note that this issue is a result of third-party factor (compatibility conflict) that the theme does not have direct control over.

Specifically:

  • The Optimization Plugin (e.g., WP Rocket): The theme cannot control how external caching and performance plugins choose to delay, defer, or lazy-render JavaScript and hidden HTML elements.
  • Gravity Forms: The theme does not control how Gravity Forms structures its AJAX system (relying on a hidden iframe in the footer) or how it initializes scripts inside hidden layouts (display: none containers like tabs).

While the theme update changed its own internal helper scripts to improve compatibility, the root cause is how these two independent third-party systems interact when elements are loaded inside a hidden state.

With that cleared up, you can check the specifics below which you can show the WP Rocket and/or Gravity Forms support to help resolve the issue.

1. WP Rocket Lazy Render Content (LRC) Integration

  • What changed: Theme X 10.8.9 and Cornerstone 7.8.9 introduced specific integrations and filters (rocket_lrc_exclusions) to exclude footers (x-colophon) and scripts from WP Rocket’s Lazy Render Content (LRC).
  • How it affects Gravity Forms: Gravity Forms relies on a hidden iframe (gform_ajax_frame_X) and inline scripts injected via the wp_footer hook to intercept and process AJAX submissions without a page reload. With LRC optimizations active, the hidden iframe and scripts inside inactive or tabbed containers can be deferred/delayed. As a result, the target iframe is either not ready or missing in the DOM when the form is submitted, preventing the onload handler from capturing the submission and swapping the form wrapper with the confirmation message.

2. Changes to Child Element Rendering (cs_render_child_elements_as_data)

  • What changed: The update resolved rendering conflicts where cs_render_child_elements_as_data (the helper that parses and nests child components inside parent elements like Tabs) threw errors when handling Dynamic Content excerpts and form output buffers.
  • How it affects Gravity Forms: When Gravity Forms processes an AJAX submission, it clears the page’s output buffer to render only the confirmation message wrapper. Prior to 7.8.9, Cornerstone’s nesting evaluation for child elements could block or interfere with the clean interception of these buffers, causing the AJAX response to return incomplete payload data.

3. Updates to Tab Toggle Scripts & Scroll Calculations

  • What changed: Cornerstone updated the JavaScript controlling tab scrolling and height calculations (specifically around equalPanelHeight and scroll states).
  • How it affects Gravity Forms: In the theme’s JS (cs-classic.7.8.9.js / cs.7.8.9.js), switching tabs dispatches a custom tco-toggle event and toggles the .x-active class to control panel visibility. Gravity Forms expects to hook into the DOM lifecycle and run gform_post_render to handle its confirmation scroll (scrollTop). Changes in how Cornerstone handles the active state transitions and height adjustments of the .x-tabs-panels container can cause the Gravity Forms scripts to fail to locate the container height, leaving the confirmation message hidden or collapsed.