tcolorbox wrong newtcolorbox formatting

Question

I'm struggling with the problem of proper wrapping of the environment which I am use in twocolumn page layout - with book class scrbook. I am using the tcolorbox package to define fancy boxes. As you can see in my code, I have two color-boxes. One for note called tcnote and other one box for definition (as is usual in a math textbook).

Unfortunately, the compilation result depends on how much text is on the page. For example if I add more dummy text, then the result is terrible as you can see on the figure below. You can play with my code by commenting/uncomenting the line \lipsum[1][2] % dummy text ON/OF

• Outside the tcnote environment, the equation in green box will print as expected.
• Inside the tcnote environment the equation is printed outside the green box which is wrong.
• The tcnote environment is split over several pages, although one page should be enough.

MNWE:

  \documentclass[fontsize=10pt,twocolumn]{scrbook}
  
  \usepackage{lipsum}  
  \usepackage[most]{tcolorbox}
  \usepackage{amsmath,mathtools}
    \newcommand\abs[1]{\ensuremath{\lvert#1\rvert}}

\newtcolorbox{tcnote}[1][]{%
  enhanced jigsaw, % better frame drawing
  enforce breakable,         % breakable,
  borderline west={2pt}{0pt}{red}, % straight vertical line at the left edge
  sharp corners, % No rounded corners
  boxrule=0pt, % no real frame,
  coltitle={red!25!black},  % Black colour for title
  colback={yellow!30},
  attach title to upper, % Move the title into the box
  right=10pt,
  compress page,
  enhanced,
  #1
}

\newtcbtheorem[auto counter,number within=chapter]{fyzdef}{DEF}{%
  colback=green!5!white,
  colframe=green!75!black,
  fonttitle=\itshape,        % \bfseries,
  enforce breakable,         % breakable,
  compress page,
  enhanced,
}{fyz}  


\begin{document}
  \section{Section}
    \lipsum[5]
    \lipsum[5]
    \lipsum[1]

    \lipsum[1][2]
    % \lipsum[1][2]  % dummy text ON/OF

    \begin{fyzdef}{Kronecker}{def016}
      \begin{equation}           
        \delta_{ij} = 
        \begin{cases} 
            1  & \text{for } i = j     \\
            0  & \text{for } i \neq j.
        \end{cases}
      \end{equation}
    \end{fyzdef}

    \lipsum[1]
    
    \begin{tcnote}    
      \lipsum[1]
      
      \begin{fyzdef}{Einstein sume rule}{def015}
        \lipsum[1][3]
        \begin{equation*}
          a'_i = \sum^3_{j=1} = \alpha_{ij}a_j.            
        \end{equation*}
        text
        \begin{equation}
          a_ia_i = a_1a_1 + a_2a_2 + a_3a_3 = \abs{a}^2 = a^2.    % (2.1)       
        \end{equation}
      \end{fyzdef}

      \lipsum[1][2]

      \begin{fyzdef}{Kronecker}{def016}
        \begin{equation}           
          \delta_{ij} = 
          \begin{cases} 
              1  & \text{for } i = j     \\
              0  & \text{for } i \neq j.
          \end{cases}
        \end{equation}
      \end{fyzdef}

      \lipsum[1][2]
      \begin{equation}
        a'_i = α_{ij} a_j         
      \end{equation}
      \lipsum[1][2]
      \begin{equation}
        α_{ik} α_{ij} = δ_{kj},    
      \end{equation}
      \lipsum[1]

    \end{tcnote}  
\end{document}

Answer 1

According to mbert's post the solution is to replace enforce breakable with simple switch breakable.

The tcolorbox documentation says that switch enforce breakable has side effect when it is used for breakable box inside a breakable box. In that case it will usually give a mess.