I am sorry if I have lost touch with this aspect, but I am surprised to know that I don’t get to see in the inspector of an action the option - ‘Repeat from this item’s’ (completion or assigned date)?
You have to have put in a Due or Deferred date for those options to appear.
Logically, that makes, sense (how can I set a repeat of Due or Deferred if there’s nothing to repeat from), but it’s not obvious or easily discoverable