AEM forms/ Adobe Form submission failure on publish instance. Error code: AEM-AF-901-004

AEM version/SP: 6.5.11

AEM forms add-on package: adobe-aemfd-linux-pkg-6.0.566-NPR-37836-B0001.zip

I've created an AEM form on author instance. The form submission is working in author instance. When I publish the form from the console & test it in publish instance, the form submission is failing. Types of submit action tested:

1. No action configured
2. Forms Portal Submit action
3. Send PDF via email
4. Send email
5. Submit to Rest endpoint
6. Use asynchronous submission - i) Redirect to URL ii) Show message

To summarize, I've tested multiple variations of form submit actions. But none of the scenario is working.

Alert message[Screenshot attached]:

[AF] [AEM-AF-901-004]: Encountered an internal error while submitting the form.

The difference that I observe in author-submission & publish-submission is that: /aem-forms-01/jcr:content/guideContainer.af.internalsubmit.jsp

This above mentioned request is failing in publish instance. In publish instance the request attributes are:

• the error code I see is Status Code: 500 Server Error
• the request header for content type is - Content-Type: text/html;charset=utf-8 whereas, in author instance the request header shows content-type as - application/json [screenshot attached].

From the error logs I understand that

• In author instance the form data is submitted as application json, as expected, and so it works.
• In publish instance the form data is submitted as plain text format and the data is expected to be in json format hence get following error:

com.adobe.aemds.guide.internal.impl.servlet.GuideInternalSubmitServlet Expected a ':' after a key at character 7 of {"guideState":{"guideDom": [...error trace continued]

Kindly provide suggestions to resolve this issue in AEM publish instance

Please refer the following screenshots.

If you have dispatcher at front, add the following rule to allow those URLs to be served:

/0229 { /type "allow" /method "POST" /path "/content/forms/af/[A-Za-z0-9-]*/[A-Za-z0-9-]*/jcr:content/guideContainer*" /extension '(jsp)'}  # allow POSTs to submit AEM Forms under /content

Review configurations at https://experienceleague.adobe.com/docs/experience-manager-65/forms/install-aem-forms/configure-aem-forms/configure-adaptive-forms-cache.html?lang=en