[NTG-context] confusing columns balancing results

13 Jul 2017

      When i try to use five balanced columns on a landscape page, i get unexpected results.

\setuppapersize[A4, landscape]
\setupbodyfont[8pt]
\language[fr]
\setupcolumns[
    n=5,
    distance=4mm,
    balance=yes,
    tolerance=tolerant]
\setupfootertexts[][]
\setuplayout[
    backspace=10mm,
    width=277mm,
    height=fit,
    topspace=10mm,
    header=0mm,
    top=0mm,
    footer=0mm,
    bottom=0mm]
\setuppagenumber[state=none]
\setuppagenumber[state=stop]
\definelayout[WithoutMarginnotes][
    location={duplex},
    grid=no,
    topspace=1cm,
    height=19cm,
    backspace=1cm,
    cutspace=0cm,
    leftmargin=0cm,
    leftmargindistance=0.4cm,
    width=fit,
    rightmargindistance=0cm,
    rightmargin=0cm]
 \setuplayout[WithoutMarginnotes]

\setuphead[section][
    align=normal,
    style=\tfa\ss,
    before={\blank},
    after={\blank[2pt]}]

When using balance=no
the page is properly typeset

\setupcolumns[
    n=5,
    distance=4mm,
    balance=no,
    tolerance=tolerant]

When using balance=yes
It looks as if the page orientation became portrait mode, as the text disappears at the bottom of the page.

\setupcolumns[
    n=5,
    distance=4mm,
    balance=yes,
    tolerance=tolerant]

Some hints as how to proceed?
Thanks
.Floris van Manen