Steps to reproduce:
1) Add a line and stacked (or line and clustered) column chart visual to your report.
2) Add a shared axis.
3) Add a measure to the Line Value property.
4) Select a single point along the line (to act as an interactive filter.)
5) Remove the measure from the Line Value property.
Expected behavior:
Line and selected point removed from visual, and implicit filter context removed from report / page.
Actual behavior:
Line is removed, but selected point remains on the visual, as well as the implicit filter context on the report.
Clicking again on the visual removes the context but not the selected point, which persists until the visual is removed.
Before removing Line Value measure:
After removing Line Value measure:
The only way to remove this dot from the visual is to remove the visual entirely; adding/removing measures or other properties on the visual has no effect.