Some days ago I discovered that my TYPO3 development installation of the 9.5.1 version stores the paragraph tag for the bodytext in tt_content table:
<p>my text</p>
So this tag is also visible in the frontend:
<p><p>my text</p><p>
In older content element there is no p tag stored:
my text
If I edit an old content element the p tag is added in database.
I defined no RTE PageTS and lib.parseFunc_RTE is untouched.