How do I turn on mark shadows?

The “Display Mark Shadow” option is turned on in my settings, but no mark shadows appear. Using the plugin “Show Anchor Cloud”, works fine, albeit showing though showing too many at once.

I have tried using the Glyphs.defaults["drawShadowAccents"] = True/False command to turn the feature off and then on again, but mark shadows still won’t show up even after rebooting the program.