\captionof changes \parskip and \parindent to 0pt
The \captionof
resets some paragraph related values but doesn't restore them but seem to rely on some grouping:
\documentclass{article}
\usepackage{caption}
\usepackage{lipsum}
\begin{document}
\noindent
\begin{minipage}{\textwidth}
\parskip=1em \parindent=1em
\lipsum[1-2]
\captionof{figure}{blub}
\lipsum[1-2]
\end{minipage}
\end{document}