How can I remove space between a subsection title and its content?

Question

I am working with LaTeX and in a section I am writing, there is a big vertical space between the title in the subsection and in the content. I don't know how to remove this space (I attach a photo for a better understanding)

In my commands before this subsection are figures without any strange command aly the one that I use (for paste a figure and for itemize).

I am using a lot of \usepackage:

    \documentclass[12pt, pdftex, pointlessnumbers, twoside, openright] 
    {scrreprt}
    \usepackage{enumitem}
    \newlist{tabitem}{itemize}{1}
    \setlist[tabitem]{wide=0pt, nosep, leftmargin= * 
     ,label=\textbullet,after=\vspace{- 
    \baselineskip},before=\vspace{-0.6\baselineskip}}
    \usepackage{a4}
    \usepackage{ae}
    \usepackage{amsbsy}
    \usepackage{amsfonts}
    \usepackage{amsmath}
    \usepackage{amssymb}
    \usepackage{amsthm}
    \usepackage{array}
    \usepackage{mathtools}
    \usepackage[german,english]{babel}
    \usepackage{bibgerm}
    \usepackage{color}
    \usepackage{epsfig}
    \usepackage{float}
    \usepackage[T1]{fontenc}
    \usepackage{graphicx}
    \usepackage[latin1]{inputenc}
    \usepackage[utf8]{inputenc}
    \usepackage{latexsym}
    \usepackage{layout}
    \usepackage{nomencl}
    \makenomenclature
    \renewcommand{\nomname}{Nomenclature}
    \usepackage{gensymb}
    \usepackage[]{geometry}
    \usepackage{afterpage}
    \usepackage[<options>]{scrlayer-scrpage} % \usepackage[automark] 
    {scrpage2}
    \usepackage{acronym} 
   \usepackage{titling}
   \usepackage{subfig}  % subfigure: Mehrere Unterbilder in einem Bild  
    \usepackage{nomencl}    % nomencl package for Symbol- oder 
    Formelverzeichnis
    %\usepackage{nomencl,etoolbox,ragged2e,siunitx}
    \usepackage{graphicx}
    \usepackage[lofdepth,lotdepth]{subfig}
    \usepackage{trfsigns}
    \usepackage{trsym}
    \usepackage[nice]{units}
    \usepackage{pythontex}
    \newcommand{\pymultiply}[2]{\py{#1*#2}}
    \usepackage{url}
    \usepackage{epstopdf}
    \usepackage[dvips]{geometry} 
    \usepackage{pdflscape}  % pdflscape: Einzelne Seiten im Querformat unter 
    PDF
    \usepackage[dvips]{rotating} % rotating: Drehen von Text und Bildern
    \newcommand{\matvar}[1]{\boldsymbol{#1}}  % Vectors/Matices bold - 
    variable
    \newcommand{\mat}[1]{\begin{pmatrix}#1\end{pmatrix}} % Matrix
    \allowdisplaybreaks
    \makenomenclature
And this is the part before that happens:
   \clearpage

    \item \textbf{Mutation:} At the end, the mutation is applied in 
    order to generate diversity and it is generated at some low 
    probability (i.e. 0.1) \cite{hesser1990towards} - see figure 
    \ref{fig:mutation}.
    \begin{figure}[!htbp]
        \centering
         \includegraphics[width=.45\textwidth]{mutation.jpg}
         \caption{Mutation example}
         \label{fig:mutation}
     \end{figure} 


    Briefly, the following flow chart depicts how the GA works (figure 
    \ref{fig:GA_chart}).
     \begin{figure}[!htbp]
      \centering
      \includegraphics[width=1\textwidth]{GA_chart.jpg}
      \caption{Flow chart from GA}
      \label{fig:GA_chart}
      \end{figure} \clearpage