The work around for displaying French versions of bilingual forms is to use the “Embed” widget instead of the MS Forms widget, and enter this code (replace yellow text “LINK of FORM” with the hyperlink to your actual form):
<iframe width="640px" height="480px" src="LINK of FORM&lang=fr-ca" frameborder="0" marginwidth="0" marginheight="0" style="border: none; max-width:100%; max-height:100vh" allowfullscreen webkitallowfullscreen mozallowfullscreen msallowfullscreen> </iframe>