Custom Multifield in Content Fragment.

You can try This : https://experience-aem.blogspot.com/2023/06/aem-cloud-service-multiple-composite-multifields-in-content-fragment-editor.html

@sesmic Your second issue is most likely due to this.

 function getMultifieldsContent() {
        $.ajax(`${CFM.EditSession.fragment.urlBase}/jcr:content/data.2.json`)
        .done(loadContentIntoMultiFields);
    }

Issue 1: Multifield gets multiplied when CF is refreshed

This issue is likely caused by the way you are adding the multifield to the content fragment model. To avoid this, make sure that you are using the sling:resourceType property to include the multifield component, rather than directly adding the multifield itself.

For example, instead of adding the following to your content fragment model:

• <multifield name="myMultifield" />

You should add the following:

• <include sling:resourceType="granite/ui/components/foundation/include" path="/path/to/multifield/component" />

Issue 2: Content fragment data is displayed as JSON when used on the page

This issue is likely caused by the way you are rendering the content fragment on your page. To render the content fragment correctly, you need to use the Content Fragment component.

For example, you could add the following to your page template:

• <cq:ContentFragment contentFragmentPath="/path/to/content/fragment" />
  This will render the content fragment on your page, using the default template for the content fragment model.

Note: The composite multifield component is not officially supported by Adobe. If you are using this component, you may encounter unforeseen issues.
Link: https://experienceleague.adobe.com/docs/experience-manager-cloud-service/content/assets/content-fragments/content-fragments-models.html?lang=en

Note: The multiple composite multifields feature is currently in beta.
Link: https://experienceleague.adobe.com/docs/experience-manager-cloud-service/content/assets/content-fragments/content-fragments-models.html?lang=en

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