How to avoid extra slide when using overlays in notes?

Question

I want to sync presentation and node contents using overlays. I tried to read the Beamer User Guide, but it's too many details and information.

This is a MWE:

\documentclass{beamer}
\usepackage{pgfpages}
\setbeameroption{show notes on second screen}


\begin{document}

\begin{frame} %<-3>
    Line 1

    \onslide<2->{Line 2}

    \onslide<3->{Line 3}

    Line 4

    \note{
        Talk about lines 1 and 4

        \onslide<2->{Talk about line 2}

        \onslide<3->{Talk about line 3}

        Don't talk about line 4
    }
\end{frame}

\end{document}

In this example, I would expect three slides, but I got four. The problem is that a replica of the last slide is also created.

The same issue happens when using \only, \visible, \uncover etc. I tried other options (<.->, <.>, <+->...) without success.

I don't want to use the itemize environment because the frame contents will not be a bullet list. Instead, it will include graphics, images and charts, as well as pseudocode. The MWE was designed only to reproduce the problem.

So far, I managed to cut off the superfluous slide by adding <-3> to the frame overlay specification (commented out in the MWE).

Well, If I could understand why the extra slide is created, I could use a more appropriate solution. :-)

Answer 1

I did not yet investigate why the 4th page is there (really strange!), but here one workaround until the problem is identified:

\documentclass{beamer}
\usepackage{pgfpages}
\setbeameroption{show notes on second screen}


\begin{document}

\begin{frame} %<-3>
    Line 1

    \onslide<2->{Line 2}

    \onslide<3->{Line 3}

    Line 4


    \note{Talk about lines 1 and 4

    }

    \note<2->{Talk about line 2

    }

        \note<3->{Talk about line 3

        }

        \note{Don't talk about line 4}

\end{frame}

\end{document}

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