tcolorbox with a header, a footer and a watermark

Question

Here is the MWE:

\documentclass[table]{standalone}
\usepackage{polyglossia, lipsum}
\usepackage[most]{tcolorbox}
\newtcolorbox{mybox}[2][]{%
  enhanced,
  before upper=\setlength{\parskip}{\bigskipamount},
  boxrule=2mm,
  bottomrule=9mm,
  watermark zoom=1,
  watermark color=black,
  watermark opacity=1,
  clip watermark,
  watermark text={\rotatebox{45}{Watermark}},
  overlay={%
    \node[white, font=\small, anchor=south, text width=\textwidth] at (frame.south) {%
        Footer \ With Two Lines};},
  title=#2,#1}
\newcommand{\xxbody}{
\lipsum[1]
}
\newcommand{\xxheading}{
  Header \ With Two Lines
}
\begin{document}
\begin{mybox}{\LARGE \xxheading{}}
\xxbody{}
\end{mybox}
\end{document}

Here is the interesting thing. With the code as it is, I get header and footer. But no watermark. Switch off the footer by commenting the overlay out, and watermark emerges.

How do I get all the three elements --- header, footer and watermark?

This is a sequel to the question here.

Answer 1

If you follow this recomendation:

\documentclass[table]{standalone}
\usepackage{polyglossia,lipsum}
\usepackage[most]{tcolorbox}
\newtcolorbox{mybox}[2][]{%
  enhanced,
  before upper=\setlength{\parskip}{\bigskipamount},
  boxrule=2mm,
  bottomrule=9mm,
  watermark zoom=1,
  watermark color=black,
  watermark opacity=.51,
  clip watermark,
  watermark text={\rotatebox{45}{Watermark}},
  overlay app={%
    \node[white, font=\small, anchor=south, text width=\textwidth] at (frame.south) {%
        Footer \ With Two Lines};
    },
  title=#2,
  #1}
\newcommand{\xxbody}{
\lipsum[1]
}
\newcommand{\xxheading}{
  Header \ With Two Lines
}
\begin{document}
\begin{mybox}{\LARGE \xxheading{}}
\xxbody{}
\end{mybox}
\end{document}