Fortnite not working?

I currently have a problem with Fortnite which never happened before, my screen is always green / white (see picture) or it is lagging all the time so that nothing can be done. I've already tried to reinstall Fortnite, unfortunately no changes.

thank you in advance in advance

LG

Go into the settings and try to reset everything to default

I've already tried it

So you can try to fix it by plugging the internet off and on again. But unfortunately I can't help with the screen.