I used titlesec to define the chapter headings for a Chinese book. However, as of texlive 2020 there are incompatibilities with Koma Script and titlesec (in my specific setting, I cannot produce a minimal example showing the conflict). I want to get rid of titlesec but I do not know how to reach the effects. What I am looking for is something to put the section number in the middle of the heading: "The 5th section".
\documentclass{scrbook}
\usepackage{titlesec}
\titleformat{\chapter}[block]{\center\Large\bfseries}{Chapter\thechapter{}Number}{20pt}{}
\titleformat{\appendix}[block]{\center\Large\bfseries}{\appendixname}{20pt}{}
\titleformat{\section}[block]{\large\bfseries}{\thesection}{10pt}{}
\titleformat{\tableofcontents}[block]{\center\Large\bfseries}{Some special string}{20pt}{}
\titleformat{\part}[block]{\center\Large\bfseries}{Part \thepart{} Number}{20pt}{}
\begin{document}
\tableofcontents
\clearpage
\part{A part}
\chapter{Introduction}
\section{foo}
\section{bar}
\end{document}

