When using the scrbook document class in combination with the subcaption package, the numbering of subfigures seems broken. Consider:
\documentclass{scrbook}
\usepackage{xcolor}
\usepackage{caption}
\usepackage{subcaption}
\captionsetup{%
format=hang,%
font=small,%
labelfont={sf,bf},%
aboveskip=0.2\normalbaselineskip,%
position=top
}
\pagestyle{empty}
\begin{document}
\begin{figure}
\caption{Black}
\label{fig1}
\centering
\rule{2cm}{2cm}
\end{figure}
\begin{figure}
\caption{More figures}
\label{fig2}
\centering
\begin{subfigure}{.3\textwidth}
\centering
\caption{Blue}
\label{fig2a}
\color{red}\rule{2cm}{2cm}
\end{subfigure}
\begin{subfigure}{.3\textwidth}
\centering
\caption{Green}
\label{fig2b}
\color{green}\rule{2cm}{2cm}
\end{subfigure}
\begin{subfigure}{.3\textwidth}
\centering
\caption{Blue}
\label{fig2c}
\color{blue}\rule{2cm}{2cm}
\end{subfigure}
\end{figure}
Figure \ref{fig1} shows a black box. Figure \ref{fig2} shows colored
boxes, where Figure \ref{fig2a} shows a red box, Figure \ref{fig2b}
shows a green box, and Figure \ref{fig2c} shows a blue box.
\end{document}
This results in the following display:
Clearly, the figure numbering in the text references is off by one for the subfigures. Instead, if I change the document class to article, it looks fine:
Why does this happen, and how can I prevent it?
