# Appendix header and references in sections [duplicate]

I am trying to use Appendix for some proofs in the thesis. The appendix looks like this:

``````\chapter{Proofs for Chapter ABC}

\section{Proof of \thmref{thm:some_theorem}}
``````

While the "Proofs for Chapter ABC" shows up correctly, the proof section seems to mess up the appendix header (see image). I double checked and the reference is correct. Any reason why it might be the case ?