Why is a page break added at the end of a column set in ConTeXt?

Question

I have a document containing some 1-column and 2-column passages, mixed, e.g.:

This sentence has no column-
s.

This part of   are balanced
the document   such that t-
has two col-   he lines are
umns which     equal.

This part of the document
has no columns. The text is
like normal.

I am using a code like this:

\definecolumnset[customcolumns][n=2]
\starttext
    This sentence has no columns.
    \startcolumnset[customcolumns]
    This part of the document has two columns which are balanced such that the lines are equal.
    \stopcolumnset
    This part of the document has columns. The text is like normal.

Whe \stoptext

When I compile this code, the last paragraph is placed on a new page, but it seems there should be enough space that it can appear on the same page.

• How can I ensure that no page break is added at the end of the column set?