How do I keep the header after adding increments in Beamer?

When I try to increment the bullet points, the header shows the section title for as many frames as the section encompasses. I want the section title to just show four dots underneath.

I have the following header in Beamer:

\documentclass{beamer} %

%%%BASICS
\usepackage[utf8]{inputenc}
\usepackage{csquotes}

%%%START THEME SETTINGS
\usetheme{Dresden}
\usecolortheme{beaver}
\usefonttheme{professionalfonts}
\setbeamertemplate{itemize item}{\color{red}$\blacksquare$}
%%%END THEME SETTINGS



%%%START APA
\usepackage[british]{babel}
\usepackage[backend=bibtex,style=authoryear]{biblatex}
\addbibresource{references.bib}
%% APA citing
%% \cite{t} - Uthor und Richter, 2010
%% \textcite{t} - Uthor und Riter (2010)
%% \parencite{t} - (Uthor & Riter, 2010)
%% \parencite[Chapt.~4]{t} - (Uthor & Riter, 2010, S. 15)
%%%END APA

\setbeamertemplate{sidebar right}{}
\setbeamertemplate{footline}{%
\hfill\usebeamertemplate***{navigation symbols}
\hspace{1cm}\insertframenumber{}/\inserttotalframenumber}

I want to create increments for the bullet points:

\begin{frame}

\section{Background}

\textbf{ABC}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}

\begin{frame}

\textbf{DEF}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}

\begin{frame}

\textbf{GHI}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}

\begin{frame}

\textbf{JKL}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}

I want to keep the header as just "Background" with 3 dots underneath it, but instead I get the following on the header ("Background" 4 times):

Solution

Sectioning commands like \section always have to be used outside of the frame. Never place them inside the frame.

\documentclass{beamer} %

%%%BASICS
\usepackage[utf8]{inputenc}
\usepackage{csquotes}

%%%START THEME SETTINGS
\usetheme{Dresden}
\usecolortheme{beaver}
\usefonttheme{professionalfonts}
\setbeamertemplate{itemize item}{\color{red}$\blacksquare$}
%%%END THEME SETTINGS



%%%START APA
\usepackage[british]{babel}
\usepackage[backend=bibtex,style=authoryear]{biblatex}
\addbibresource{references.bib}
%% APA citing
%% \cite{t} - Uthor und Richter, 2010
%% \textcite{t} - Uthor und Riter (2010)
%% \parencite{t} - (Uthor & Riter, 2010)
%% \parencite[Chapt.~4]{t} - (Uthor & Riter, 2010, S. 15)
%%%END APA

\setbeamertemplate{sidebar right}{}
\setbeamertemplate{footline}{%
\hfill\usebeamertemplate***{navigation symbols}
\hspace{1cm}\insertframenumber{}/\inserttotalframenumber}


\begin{document}

\section{Background}

\begin{frame}



\textbf{ABC}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}

\begin{frame}

\textbf{DEF}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}

\begin{frame}

\textbf{GHI}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}

\begin{frame}

\textbf{JKL}

\begin{itemize} [<+->]
    \item lol
\item what's up
\end{itemize}

\end{frame}


\end{document}