I'm writing my dissertation and everything worked fine until I upgraded to texlive 2019. Now my table of contents suddenly starts in the middle of the page. It worked fine before, please help!
\documentclass{book}
\begin{document}
\tableofcontents
\pagebreak
abcd
\chapter{title}
\section{title}
abcd
\end{document}
\pagebreak
but\newpage
(see also \pagebreak vs \newpage)\pagebreak
effect.