I write a presentation using pdfscreen, with an old version \RequirePackage[2019/01/01]{latexrelease}. When I try to make table of content, the names of the sections are broken, displaying .1. * as a title, and all the section and subsection are formated with 0.x. Plus, the 3 first section/part are skipped (see image below).
The whole code :
\documentclass{article}
% Packages
\RequirePackage[2019/01/01]{latexrelease}
\usepackage{amsmath, amssymb, latexsym, stmaryrd, amsthm}
\usepackage{mathptmx, helvet}
\usepackage[pdftex]{graphicx}
\usepackage[utf8]{inputenc}
\usepackage[french]{babel}
\usepackage{color, url}
\usepackage{covington}
\usepackage{hyperref}
\usepackage{titlesec}
\usepackage{array}
\usepackage{proof}
% Couleurs
\definecolor{boeuf}{rgb}{0.58,0,0.15}
\definecolor{brun}{rgb}{0.4,0.1,0.2}
\definecolor{bouteille}{rgb}{0.02,0.3,0.3}
\definecolor{marine}{rgb}{0.3,0.3,0.7}
% Configuration de pdfscreen
\usepackage[screen, sectionbreak, orange]{pdfscreen}
\margins{1.6in}{.7in}{.6in}{.6in}
\screensize{5in}{6.7in}
\overlay{fonds/bonbons}
% Commandes personnalisées
\newcommand{\blu}[1]{\textcolor{marine}{\bf #1}}
\newcommand{\forces}{\Vdash}
\newcommand{\existe}{\exists}
\newcommand{\pourtout}{\forall}
\newcommand{\implique}{\rightarrow}
\newcommand{\et}{\land}
\newcommand{\ou}{\lor}
\newcommand{\saut}{\vfill}
\newcommand{\carre}{\square}
\newcommand{\losange}{\Diamond}
% Configuration du titre et des auteurs
\title{{\large \bf \qquad Blabla logic, Elevator \
\blu{Referent : xxxxx XXXXXX}}}
\author{
\small\color{boeuf} John DOE\
\small\color{boeuf} Janne DOES\
\footnotesize Due 25 may 2023\}
\setlength{\parindent}{0pt}
\date{}
\renewcommand\part[1]{%
\clearpage
\vspace{5em}
\Large
\begin{center}\stepcounter{part}\textcolor{marine}{\bf \Alph{part}\quad #1 }\end{center}
\vspace{5em}
\large
\clearpage
}
\renewcommand\thepart{\Alph{part}}
\newcounter{sec}[part]
\setcounter{sec}{0}
\renewcommand\section[1]{
\clearpage
\par\bigskip
\stepcounter{sec}
\textcolor{bouteille}{\Large \bf \Alph{part}.\arabic{sec}.\quad #1}\newline\par
}
\setlength{\parskip}{0pt plus1fill}
\begin{document}
\large
\maketitle
\newpage
\tableofcontents
\pagebreak
\newpage
\part{Introduction}
\section{Présentation}
\section{Modal Logic}
\subsection{Box et losange}
...
\end{document}
I've searched across stackexchange and Google, but I didn't find anything relevant. I have absolutely no idea from where the bug comes from. Thanks in advance for any help !
