When you have data points in a scatter chart with identical x and y values, you can access only one of them.
It seems that all other data points are covered under the top data point.
If you click on the point, only one element gets selected.
If you hover over the odata point, you get only information about one data point in tool tips.
It should be possible to - at least as an option - to access all identical entries when hovering or selecting the point in the scatter chart.
One option would be to have a region select, so one could select all points by marking the region around them.
But it would be more convinient toget all identical points by just clicking or when hovering. There is no particular reason for one of the entries to get selected over the others. They are all valid data "in their own right" at least if you decide you want this behaviour.
I totally understand that one might prefer the current behaviour in different circumstances
