Activate Fortnite 3D sound?

Can someone help me with the following problem: I want to activate the 3D sound in Fortnite with my headset. In the settings for "3D headphones" it says "3D sound is activated / deactivated in the settings of the operating system". I did this and still this message still appears and I can't turn on the 3D sound. My new Mpow headset should be compatible.

There's something else: can't be used together with "visualize sound effects".

Yes, but I've already figured that out