Magento2 Page Builder – Empty a Tag Becomes  

You have a couple of options. The simplest is using the Text content type to include the widget using the standard TinyMCE widget feature.

Your other option is to create a new content type which wraps your widget in a Page Builder content type. Our Products content type does exactly this, it's just an interface for the Catalog Product List widget.

products.xml contains a mass converter to create the widget directive:

view/adminhtml/pagebuilder/content_type/products.xml

<converters>
    <converter component="Magento_PageBuilder/js/content-type/products/mass-converter/widget-directive" name="widget_directive">
        <config>
            <item name="html_variable" value="html"/>
        </config>
    </converter>
</converters>

Which in turn within widget-directive.ts (or JS depending on which source you're viewing) we create the standard product list widget directive:

view/adminhtml/web/ts/js/content-type/products/mass-converter/widget-directive.ts:

    public toDom(data: ConverterDataInterface, config: ConverterConfigInterface): object {
        const attributes = {
            type: "Magento\\CatalogWidget\\Block\\Product\\ProductsList",
            template: "Magento_CatalogWidget::product/widget/content/grid.phtml",
            anchor_text: "",
            id_path: "",
            show_pager: 0,
            products_count: data.products_count,
            type_name: "Catalog Products List",
            conditions_encoded: this.encodeWysiwygCharacters(data.conditions_encoded || ""),
        };

        if (attributes.conditions_encoded.length === 0) {
            return data;
        }

        set(data, config.html_variable, this.buildDirective(attributes));
        return data;
    }

You can read more about mass converters here: https://devdocs.magento.com/page-builder/docs/reference/configurations.html#mass-converter

You can look to duplicate the Products content type and modify it to your needs. On a high level, it just feeds it's configured form fields into the directive's parameters.

Alongside the above, we have a great step by step tutorial on how to create a new content type available here: https://devdocs.magento.com/page-builder/docs/create-custom-content-type/overview.html

You should see this issue if you've upgraded to magento 2.3.5-p2. This issue comes up when you have more than one page builder elements on the same page. Mostly causes issue when you have a custom page builder element on page for your custom attribute.

To fix this issue, in your uiComponent add the following item nodes under wysiwyg config.

<item name="is_pagebuilder_enabled" xsi:type="boolean">true</item>
<item name="pagebuilder_button" xsi:type="boolean">true</item>

You can find full example on github issue page https://github.com/mirasvit/module-blog/issues/162

Note: This has been fixed in Magento 2.3.6 https://devdocs.magento.com/page-builder/docs/release-notes.html#133-for-magento-commerce-236