I have a code with sections, subsections, enumerations in two-columns style:
\RequirePackage{fix-cm}
\documentclass[fontsize=8.5pt,DIV=calc]{scrbook}
\usepackage[T1]{fontenc}
\usepackage[ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage{helvet}
\usepackage{geometry}
\geometry{a4paper,left=15mm,right=15mm, top=26mm, bottom=17mm}
\renewcommand{\familydefault}{\sfdefault}
\usepackage{multicol}
\usepackage{xcolor}
\usepackage{mdframed}
\usepackage{paralist}
\setlength\parindent{0pt}
\setlength\columnsep{5mm}
\renewcommand\familydefault{\sfdefault}
\renewcommand{\labelitemi}{\textcolor{black!60}{\raisebox{0.5mm}{\rule{1.8mm}{1.8mm}}}}
\newcommand{\zitiert}[1]{\flqq{#1}\frqq}
\usepackage{enumitem}
\setitemize{leftmargin=*}
%FOR GREY RECTANGLE
\addtokomafont{section}{\large}
\makeatletter
\renewcommand\sectionlinesformat[4]{%
\ifstr{#1}{section}
{\setlength\fboxsep{1.75mm}%
\colorbox{black!15}{\raisebox{0pt}[\height][0pt]{%
\parbox[b]{\dimexpr\linewidth-2\fboxsep\relax}{%
\raggedsection\@hangfrom{\hskip#2#3}{#4}%
}}}}
{\@hangfrom{\hskip#2#3}{#4}}%
}
\renewcommand\sectionformat{%
\makebox[10mm][r]{\thesection\autodot\hspace{5mm}}
}
\makeatother
\usepackage{lipsum}
\begin{document}
\begin{multicols}{2}
Some random text....
\subsection{One}
\section{Two}
\subsection{Three}
\lipsum[1]
\subsection{Four}
\lipsum[1]
\subsection{Five}
\lipsum[1]
\subsection{Six}
\lipsum[1]
With an enumeration:
\begin{compactenum}[a)]
\item \lipsum[1]
\item \lipsum[1]
\end{compactenum}
\ \\
\lipsum[1]
\end{multicols}
\end{document}
Unfortunately, the rows of the two columns are not on the same "level" (as you can see in the picture below - marked with the red line).

Is there a way (general) way to solve this problem?