When using Page Layouts, Editor creates elements that are only styled like headings or paragraphs

When using Page Layouts, Editor creates elements that are only styled like headings or paragraphs. This can then affect the following

• The Table of Contents macro would not see headings correctly
• Exported PDFs will not show headings correctly
• Screen readers looking for a heading will not show it correctly
• On screen, the CSS styling will look incorrect

Reproducing Steps

To reproduce, use a few section layouts, and add text like this:

<ac:layout>
<ac:layout-section ac:type="single">
<ac:layout-cell>
<p>intro paragraph</p>
<h2>First heading</h2>
<p>text</p>
<h2>Second heading</h2>
<p>text</p>
</ac:layout-cell>
</ac:layout-section>
<ac:layout-section ac:type="single">
<ac:layout-cell>
<p>
<br/>
</p>
</ac:layout-cell>
</ac:layout-section>
</ac:layout>

Now, in the editor normally (not code view) delete the "intro" paragraph.

Expected

The h2 style moving up as expected

Actual

It is replaced by spans as observed in the storage format

<ac:layout>
<ac:layout-section ac:type="single">
<ac:layout-cell>
<p>
<span style="font-size: 20.0px;letter-spacing: -0.008em;">First heading</span>
</p>
<p>text</p>
<h2>Second heading</h2>
<p>text</p>
</ac:layout-cell>
</ac:layout-section>
<ac:layout-section ac:type="single">
<ac:layout-cell>
<p>
<br/>
</p>
</ac:layout-cell>
</ac:layout-section>
</ac:layout>

Other Notes

This does not occur when layouts are not used. Similar to CONFSERVER-29193 but only when using page layouts