MediaSound component attenuation radius preview disappears from viewport when changed. You need to deselect and re-select the actor when you want to see a preview of your attenuation fall off. You don;t get a live preview of you newly adjusted settings,
Add a Media sound component to a Blueprint.
Add the new BP to the world.
In the Media Sound Component, enable Allow Specialization and Override Attenuation.
Change Inner Radius or Falloff Distance and the preview sphere volumes in the viewport will disappear.
Deselect the actor and re-select it to see the volumes again, but changing the Radius or Falloff Distance again will cause them to disappear again.
There's no existing public thread on this issue, so head over to AnswerHub just mention UE-54079 in the post.