Seeing stray richtext in QTextEdit when using selection to clear/update

Seeing stray richtext in QTextEdit when using selection to clear/update

If richtext is loaded once, it looks fine, but if I use a "hack" to
clear/replace the text then I end up getting stray rich text at the top
of the text edit widget.

Test case provided in attached example_application.tar.gz and the resulting error can be seen in the attached example.png