Your own crosshair disappears in Fortnite?

I have the following problem: I created my own crosshair overlay. This is only displayed to me in Fortnite, for example, if I'm currently on the 2nd monitor with my mouse. When I switch back to the other monitor in Fortnite, the crosshairs are gone. How can I make it that the crosshair is always displayed, even during Fortnite?

Is not allowed

Yes also believe