Break apart drop shadow effect, select shadow image, apply Gaussian blur effect. I hate the way even 2019 renders the shadow. Not smooth...not smooth at all.
Okay, yes, it is possible to create a macro to do it. Ideally a "selectable" value of blur as a fixed value may not be appropriate for every occasion.
I don't have any personal experience with it, but you might look at Sancho's DropShadowDocker.