text: What a wonderful community this is, taking such care and attention about queries such as this, over such a long time period too. 
  Anyway: I can confirm that I have revisited the mapping point in question here, and it now behaves as expected in Mapometer. Thank you all for your assistance; we may never know whether it was an app-based on map-based issue, but it's now resolved. 
  Thank you again everyone for your help.