Weird Display Issue with matrices and hyperref

Question

I was trying to use a math term as a section header that included a pair of stacked arrows that I displayed using smallmatrix. However later in my code I am using hyperref as well and when I added the hyperref library a weird display error happened with the header. Here is an abridged version of the code that still produces the error. It also throws a countless number of errors within latex, however removing the hyperref library and the hyperref formatting line makes all these errors dissapear.

\documentclass{amsart}
\usepackage[margin=1in]{geometry}
\usepackage{amsmath, hyperref}
\newcommand{\CC}{\mathbb{C}}
\hypersetup{colorlinks=true, linkcolor=blue}
\title{Plucker Relations}
\author{Riley Paddock}
\begin{document}
\maketitle
\section{$Gr_{(4, 2)}(\CC^6 \begin{smallmatrix}\leftarrow\ \leftarrow\end{smallmatrix}\CC^5)$}
\end{document}

Here is how the file displays:

The error is the weird line that displays after the section header as you can see in the image.