tcolorbox disable repeated text in overlayed node

Question

In the following MWE (built from https://tex.stackexchange.com/a/170767/69378) I have demonstrated that title text in an overlayed tcolorbox node gets repeated across page breaks.

I have checked the manual against each of the arguments being configured, and tried commenting out ones I thought might be the culprit, but I am always left with this repeated title. Normally this is a fine feature, but I want to be able to selectively turn this off, when the tcolorbox is small and repeating this title just increases clutter.

What is forcing this repeat?

\documentclass{article}
\usepackage[left=60pt,top=60pt,right=60pt,bottom=60pt]{geometry}
\usepackage{xcolor}
\usepackage{lipsum}
\usepackage{kantlipsum}
\usepackage{enumitem}
\usepackage[many]{tcolorbox}

\setitemize{nolistsep,labelsep=1ex,leftmargin=*}

%% colors---
\definecolor{lightgray}{gray}{0.8}

%%items--
\newlist{items}{description}{1}
\setlist[items]{align=right,font=\normalfont, leftmargin=1.8in,style=nextline,labelsep=1em,}

%% leftrulebox---
\tcbuselibrary{skins,breakable}
\newtcolorbox{leftrulebox}[1][]{
    colback=white,
    boxrule=10pt
    left=0.5ex,
    top=0pt,
    arc=0pt,
    outer arc=0pt,
    enlarge left by=1.8cm,
    enlarge right by=-\dimexpr1.8cm+\parindent\relax,
    right=\dimexpr1.8cm+\parindent\relax,
    leftrule=1pt,
    rightrule=0pt,
    toprule=0pt,
    bottomrule=0pt,
    breakable,
    nobeforeafter,
    enhanced jigsaw,
    overlay={
      \node[anchor=north east,inner ysep=0pt,align=right,text width=1.8cm] 
        at ([yshift=-0.55ex]frame.north west) {\hfill#1};
    },
    before=\vskip2\itemsep\noindent
  }

\begin{document}

\section*{Sample}

\begin{leftrulebox}[Text Title]
\kant[1]
\kant[2]
\kant[3]
\kant[4]
\kant[5]
\end{leftrulebox}

\end{document}

**UPDATE: MWE 2 for intermitent solution **

\documentclass{article}
\usepackage[left=60pt,top=60pt,right=60pt,bottom=60pt]{geometry}
\usepackage{xcolor}
\usepackage{lipsum}
\usepackage{kantlipsum}
\usepackage{enumitem}
\usepackage[many]{tcolorbox}

\setitemize{nolistsep,labelsep=1ex,leftmargin=*}

%% colors---
\definecolor{lightgray}{gray}{0.8}

%%items--
\newlist{items}{description}{1}
\setlist[items]{align=right,font=\normalfont, leftmargin=1.8in,style=nextline,labelsep=1em,}

%% leftrulebox---
\tcbuselibrary{skins,breakable}
\newtcolorbox{leftrulebox}[1][]{
    colback=white,
    boxrule=10pt
    left=0.5ex,
    top=0pt,
    arc=0pt,
    outer arc=0pt,
    enlarge left by=1.8cm,
    enlarge right by=-\dimexpr1.8cm+\parindent\relax,
    right=\dimexpr1.8cm+\parindent\relax,
    leftrule=1pt,
    rightrule=0pt,
    toprule=0pt,
    bottomrule=0pt,
    breakable,
    nobeforeafter,
    enhanced jigsaw,
    %overlay={
    %   \node[anchor=north east,inner ysep=0pt,align=right,text width=2.6cm] 
    %   at ([yshift=0.5ex]frame.north west) {\hfill#1};%-0.55 hold yshift
    %},
    extras first={
        overlay={%
            \node[anchor=north east,inner ysep=0pt,align=right,text width=2.6cm] 
            at ([yshift=-0.5ex]frame.north west) {\hfill#1};
        },
    },
    extras middle and last={%
        overlay={%
            \node[anchor=north east,inner ysep=0pt,align=right,text width=2.6cm] 
            at ([yshift=-0.5ex]frame.north west) {\hfill};
        },
    },
    %before=\vskip2\itemsep\noindent
    before=\vskip\itemsep\noindent
  }

\begin{document}

\section*{Sample}

\begin{leftrulebox}[Text Title 1]
\kant[1]
\end{leftrulebox}

\begin{leftrulebox}[Text Title 2]
    \kant[2]
\kant[3]
\kant[4]
\kant[5]
\end{leftrulebox}

\begin{leftrulebox}[Text Title 3]
    \kant[3]
    \kant[4]
    \kant[5]
\end{leftrulebox}

\end{document}

Answer 1

Imho you are looking for the overlay unbroken and first key:

\documentclass{article}
\usepackage[left=60pt,top=60pt,right=60pt,bottom=60pt]{geometry}
\usepackage{xcolor}
\usepackage{lipsum}
\usepackage{kantlipsum}
\usepackage{enumitem}
\usepackage[many]{tcolorbox}

\setitemize{nolistsep,labelsep=1ex,leftmargin=*}

%% colors---
\definecolor{lightgray}{gray}{0.8}

%%items--
\newlist{items}{description}{1}
\setlist[items]{align=right,font=\normalfont, leftmargin=1.8in,style=nextline,labelsep=1em,}

%% leftrulebox---
\tcbuselibrary{skins,breakable}
\newtcolorbox{leftrulebox}[1][]{
    colback=white,
    boxrule=10pt
    left=0.5ex,
    top=0pt,
    arc=0pt,
    outer arc=0pt,
    enlarge left by=1.8cm,
    enlarge right by=-\dimexpr1.8cm+\parindent\relax,
    right=\dimexpr1.8cm+\parindent\relax,
    leftrule=1pt,
    rightrule=0pt,
    toprule=0pt,
    bottomrule=0pt,
    breakable,
    nobeforeafter,
    enhanced jigsaw,
    overlay unbroken and first={
       \node[anchor=north east,inner ysep=0pt,align=right,text width=2.6cm]
       at ([yshift=0.5ex]frame.north west) {\hfill#1};%-0.55 hold yshift
    },
    %before=\vskip2\itemsep\noindent
    before=\vskip\itemsep\noindent
  }

\begin{document}

\section*{Sample}

\begin{leftrulebox}[Text Title 1]
\kant[1]
\end{leftrulebox}

\begin{leftrulebox}[Text Title 2]
    \kant[2]
\kant[3]
\kant[4]
\kant[5]
\end{leftrulebox}

\begin{leftrulebox}[Text Title 3]
    \kant[3]
    \kant[4]
    \kant[5]
\end{leftrulebox}

\end{document}

Answer 2

One can try the extras first and extras middle and last options to provide the specific overlay (with the text) for the first box (the first broken one) and leave the overlay without #1 for the middle and last boxes in the break sequence.

\documentclass{article}
\usepackage[left=60pt,top=60pt,right=60pt,bottom=60pt]{geometry}
\usepackage{xcolor}
\usepackage{lipsum}
\usepackage{kantlipsum}
\usepackage{enumitem}
\usepackage[many]{tcolorbox}

\setitemize{nolistsep,labelsep=1ex,leftmargin=*}

%% colors---
\definecolor{lightgray}{gray}{0.8}

%%items--
\newlist{items}{description}{1}
\setlist[items]{align=right,font=\normalfont, leftmargin=1.8in,style=nextline,labelsep=1em,}

%% leftrulebox---
\tcbuselibrary{skins,breakable}
\newtcolorbox{leftrulebox}[1][]{
    colback=white,
    boxrule=10pt
    left=0.5ex,
    top=0pt,
    arc=0pt,
    outer arc=0pt,
    enlarge left by=1.8cm,
    enlarge right by=-\dimexpr1.8cm+\parindent\relax,
    right=\dimexpr1.8cm+\parindent\relax,
    leftrule=1pt,
    rightrule=0pt,
    toprule=0pt,
    bottomrule=0pt,
    breakable,
    nobeforeafter,
    enhanced jigsaw,
    extras first={
    overlay={%
      \node[anchor=north east,inner ysep=0pt,align=right,text width=1.8cm] 
        at ([yshift=-0.55ex]frame.north west) {\hfill#1};
    },
    },
    extras middle and last={%
      overlay={%
        \node[anchor=north east,inner ysep=0pt,align=right,text width=1.8cm] 
        at ([yshift=-0.55ex]frame.north west) {\hfill};
      },
    },
    before=\vskip2\itemsep\noindent
  }

\begin{document}

\section*{Sample}

\begin{leftrulebox}[Text Title]
\kant[1]
\kant[2]
\kant[3]
\kant[4]
\kant[5]
\end{leftrulebox}

\end{document}