Under various circumstances the Google Maps visualization drill down fields in the tooltip are blank. Normally it should show “By X” and by “By Y” where X and Y are drill down fields defined for the location being visualized. However, these field names can show up as empty such that you see “By “ (just the By with no field) for each field that should be listed.
Compare:
vs.
When viewing the visualization in an Explore I saw this for Point plot mode but not for Automagic Heatmap plot mode. However, when viewing in a Dashboard it happens for both.
Is this a bug or is there some setting I need to tweak?