I'm not sure this is the right place to answer such a question considering that's probably not specifically correlated to Photshop and probably not even an error or problematic but just normal behaviour. Still, i'll make a try.
Might be kind of a stupid question but i'm pretty ignorant in the field and i can't understand what's happening here.
I'd want to blur a black elipse but when i try applying a gaussian blur to the shape this dark circle appears at the center of it. Such behaviour doesn't reproduce with other colors i tried.
The image below represents two exactly identical elipses with gaussian blur applied at 30% intensity. As you can see the black one presents the "problem" i described. Is this normal and if it is why does it happen? Thanks in advance and bye.