[NTG-context] Cannot get upright integral in stixtwo anymore

Hi, the code \setupbodyfont[stixtwo] \starttext \startTEXpage[offset=2bp] $\displaystyle \int x^2\,dx=\frac{x^3}{3}+C$\par \setupmathematics[stylealternative={upright}] $\displaystyle \int x^2\,dx=\frac{x^3}{3}+C$\par \stopTEXpage \stoptext used to give an "upright" integral sign in the second example, but not anymore. Is there a new way to obtain this? Best regards, Mikael