40 FPS in Fortnite?

Yesterday I played Fortnite on my gaming laptop (ASUS TUF GAMING FX505DV HN311T) and had over 200 FPS smoothly, I don't know whether that was a bug or not but it definitely packs 144 FPS smoothly. And today I started Fortnite again and saw that I have 40-60 FPS (see attachment). I've reset and re-set all the settings, etc. But it stays below 60 FPS. Can someone please explain to me step by step what I have to do to get back to 144 FPS. The laptop definitely manages over 144 FPS…

Update graphics driver

How and where can I do this?

Task manager.

https://www.nvidia.de/.../172590/de

should be the right one for the 2060

Thanks

Either as from the Kel from the Internet or in nvidia's own software where you can always get the latest for your card