I could send you the minor I have put up.

> Sent: Thursday, February 11, 2021 at 9:21 AM
> From: "Stefan Monnier" <monnier@iro.umontreal.ca>
> To: help-gnu-emacs@gnu.org
> Subject: Re: tex-mode.el
>
> > Still same problem
> >
> > (setq-local tex-fontify-script nil)
> > (font-lock-flush)
> >
> > It works in the sense that when I call it the new text is not
> > fontified.  However, the text that was already fontified remains
> > fontified.
>
> Works for me, so maybe you want to provide a more detailed description
> of what you do, and what is and isn't properly re-fontified.
>
>
>         Stefan
>
>
>