[NTG-context] color conversion eats note

uncommenting the following \setupcolors changes magenta to black when running luatex. but when running luametatex the footnote is crippled to «error»: \starttext \definestartstop[UL][color=magenta] %\setupcolors[state=stop,conversion=never]% <- bw with lualatex, but «error» with luametatex? \input ward \footnote{foo foo \startUL{}foo\stopUL{} foo foo foo foo foo \startUL{}foo\stopUL{} error} \stoptext Steffen