Package trackchanges: problem with UTF8

It seems that loading the package soulutf8 before trackchanges solves the problem

\documentclass[12pt]{article}
\usepackage[utf8]{inputenc} 
\usepackage{soulutf8}
\usepackage{trackchanges}
\begin{document}
    text \remove{öäü}
\end{document}

This seems to be an issue of the internally used soul package (Strike-Out, UnderLine) used for highlighting of the changes. It reads the content stepwise and splits the Unicode characters in two. You might find help in the soul manual.

As a workaround I would redefine the used highlighting macros, e.g. \stcolor for the given example. Here I use a simple \textcolor (from the already loaded xcolor package) instead of the soul code.

\documentclass[12pt]{article}
\usepackage[utf8]{inputenc}
\usepackage{trackchanges}
\renewcommand{\stcolor}[2]{\textcolor{#1}{#2}}
\begin{document}
    text \remove{öäü}
\end{document}

This works for me.