[NTG-context] [***SPAM***] float placement riddle

Please can someone explain why the column before the floating figure is empty? I thought that the figure would float through the text to the first location with sufficient space. That appears not te be the case: the input behind the figure does not typeset before it although there is ample space for the text that now follows the picture. The code is roughly: \setupcolumns[n=2] \startcolumns <several paragraphs> \placefigure[][figuur:zw]{Street.} {\externalfigure[zw][width=0.8\textwidth]} \par <small paragraph following picture> <several paragraphs extending to next page> \stopcolumns How to get Hans van der Meer [cid:796264A3-FA21-43EB-894F-3C74D1E4D519@fritz.box]