Example:
\documentclass[10pt,a4paper]{article}
\usepackage{hyperref}
\usepackage{mathtools}
\begin{document}
Some Text
\begin{equation}
\label{eq:1}
d(k_{a},k_{b})=
\end{equation}
Some Text
\begin{subequations}
\label{eq:2}
\begin{equation}
\label{eq:2-1}
s(k_{a},k_{b})
\end{equation}
Some Text
\begin{equation}
\label{eq:2-2}
d(k_{a},k_{b})=
\end{equation}
\end{subequations}
Some Text \\
\autoref{eq:1}.
\autoref{eq:2}.
\autoref{eq:2-1}.
\autoref{eq:2-2}.
\end{document}
2-1, and 2-2 point into wrong places despite having the correct name.
hyperrefshould always be loaded last. To wit, if you loadhyperrefafter rather than beforemathtoolsand recompile the test document, clicking on the hyperlinks will take you to the correct locations. – Mico Jan 02 '20 at 00:16