Magento – CMS and Block content warning Magento 2.4.2

I guess you are mixing CMS blocks and pages. The home page content is as CMS page and what you are doing in your local.xml is adding a CMS block.

So you have two options. Either create a new CMS block inside of Magento admin or create your custom block type, pull the content of the CMS page there and then display it.

If you are not quite experienced with Magento I would suggest the first approach.

To create your custom block type you have to create a module (this answer will not cover it) and inside you have to create a block class with the following content:

<?php

class YourPackage_YourModule_Block_Page extends Mage_Core_Block_Template
{
    public function getContent()
    {
        $page = Mage::getModel('cms/page');
        $page->setStoreId(Mage::app()->getStore()->getId())
            ->load($this->getPageId(),'identifier');

        return $page->getId() ? Mage::helper('cms')->getPageTemplateProcessor()->filter($page->getContent()) : '';
    }
}

Then in your local.xml you can add your block to any exiting layout like this:

<reference name="...">
    <block type="your_module_alias/page" name="block_name" template="cms/cms-page-content.phtml">
        <action method="setPageId"><page_id>your_page_identifier</page_id></action>
    </block>
</reference>

And at last in your template at base/default/templates/cms/cms-page-content.phtml:

<?php $this->getContent() ?>

Have you tried adding a root block between label and content? As follows:

<reference name="root">
    <block type="core/template" name="my_header" as="my_header" template="cms/default/my_header.phtml" />
</reference>

So, for clarity:

<cms_page translate="label">
    <label>CMS Pages (All)</label>
    <!-- ROOT BLOCK HERE -->
    <reference name="content">
        ....
    </reference>
</cms_page>

This block can be called in the view using getChildHtml('my_header').