No Location Found on Find My even though devices are visible

SOLVED: Even though location shared etc, a person (A) shows up as No Location Found on Find My app of the persons (B) they shared with. Solution found was on (A) iPhone to go to Settings/Privacy/Location Services and scroll all the way to the bottom of the list, to the end, and select System Services. In there there is a set of switches including Find My (which is probably, and properly, ON) - but there is also a second switch further down, Share My Location which must ALSO be set to ON. If that is off, then the No Location Found error will be seen on (B) iPhones.