Consider following MWE:
\documentclass{article}
\usepackage[most]{tcolorbox}
\definecolor{block-gray}{gray}{0.95}
\newtcolorbox{zitat}[2][]{%
breakable, % IMPORTANT
colback=block-gray,
boxrule=0pt,
arc=0pt,
boxsep=0pt,
enhanced jigsaw,
borderline west={4pt}{0pt}{gray},
title={#2\par},
colbacktitle={block-gray},
coltitle={black},
fonttitle={\large\bfseries},
attach title to upper={},
box align=top,
#1,
}
\begin{document}
\section*{Quotes} % commenting removes difference
\begin{itemize}
\item \begin{zitat}{Quote 1}
Space: the final frontier.
\end{zitat}
\item \begin{zitat}{Quote 2}
A long time ago in a galaxy far, far away\ldots
\end{zitat}
\item \begin{zitat}{Quote 2}
A long time ago in a galaxy far, far away\ldots
\end{zitat}
\end{itemize}
\end{document}
which produces following output
As you can see there is more vertical space before tcolorbox in the first item compared to the last two ones.
This disappears when I remove the section command.
What can I do to fix this without manually adjusting it?
(TexLive 2016 on OSX El Capitan, tcolorbox 2016/11/18 version 3.96)
UPDATE:
It appears that the option breakable
is responsible. There is a related option vfill before first
:
/tcb/vfill before first=true|false
Inserts a\vfill
at the begin of the first partial box to move this partial box to the end of the current page. This may be used as an alternative to/tcb/height fixed
for=first
to get justified columns or pages. The\vfill
is not inserted, if the box gets not actually broken.
However, removing breakable
and inserting a \vfill
does not reproduce this issue. I guess the author of tcolorbox
probably knows what is going on.
I report this to https://github.com/T-F-S/tcolorbox/issues
breakable
to avoid vertical scrolling on tex.stackexchange.com which appears to be responsible.