I'm defining item groups in ConTeXt and I find the following issue: combining the "text" parameter with others automatically disables "left" and "right" keys, so numbers always appear enclosed in parentheses.

%What I expect:
%I. This ain't right
%What I get:
%(I) This ain't right
\defineitemgroup[erroneous]
\setupitemgroup[erroneous][1][R,text,continue][left=,right=.,stopper=]
\starttext
\starterroneous
\startitem This ain't right \stopitem
\stoperroneous
\stoptext

Maybe a bug, I want to know how to get the expected result. Thank you in advance.