don't know, if this is already known, but I encounter a bug in the legend of visualizations in 6.5.4 of kibana.
I have just a visualization with legend:
If I click on one legend entry the legend should get unfolded, that I can filter for or against one of the entries and that I can pick the colors.
It works fine, as long as the unfolded legend fits into the space of the visualization. If it dont' the legend flickers and collapses again. If I switch to fullscreen and the legend has enough room to unfold, it works as expected.
Can you reproduce? If so, please fix it.