I do number my chapters with roman numerals with:
\setuphead[chapter][conversion=Romannumerals]
I would expect then that sections are numbered roman.arabic for example IX.1
This is not the case. While the chapter is numbered IX the sections are numbered 9.1 instead of IX.1.
The numbering of floats with \placefigure luckily does the caption numbering right, i.e. there I see IX.1 as its number.
Using
\setuphead[section][conversion=Romannumerals]
fails because then IX.I is produced, clearly not what is desired although the caption numbering is not influenced.
Using
\setuphead[section][number=no]
does not help either, because then the captions loose their chapter number.
What to do?