[NTG-context] flushleft nbsp with unequal width

Hello, with \setupalign[flushleft] non-breakable space has different width than regular space. With pure \rightskip0pt plus 1fill all spaces are equal. Is this wanted behaviour or do I miss additional settings? \showmakeup[glue] \startTEXpage[width=80mm,offset=5mm] \rightskip0pt plus 1fill woo woo woo woo woo woo woo woo woo woo \blank \setupalign[flushleft] woo woo woo woo woo woo woo woo woo woo \stopTEXpage MWE also in the attachment to preserve nbsp. Regards, Jano