The GenTokens option begin on weekstart is ignored when GenTokens token is inside a minicalendar (ie. placed in the same box, and after, a minicalendar token).
If you want a GenTokens inside a minicalendar to start on the start of the week that contains the 1st of the month, then use the :ws embedded tokens weekstart minicalendar modifier instead.
Topic 178160, last updated on 19-Apr-2020