Inconsistent drag-to-select chart data source

Question

Excel provides a way to modify selections for chart data sources by changing the selection window, but the behavior is inconsistent at best. The first time I try to change a range selection, the linked component (e.g. x for y, or y for x) changes in tandem. That is a reasonable and useful feature.

But in all subsequent attempts, this behavior changes and the linked component does not change along with my range selection............

This might also be reasonable in certain circumstances, maybe. But it's quite stupid here since these ranges are clearly linked.

How do I get back the linked drag-and-drop selection behavior?

Answer 1

Oops I wasn't paying enough attention. It's a matter of chart selection versus series selection. Selecting the entire chart produces the linked range selection behavior I desired.

(Whether or not selecting the chart will actually display the data range selection markers is a different issue but in that case, repeated attempts will generally make it work.)