PC monitor waves1?

I have a 144hhz monitor and when I set the FPS limitation to 144FPS in Fortnite such waves appear on my monitor and if I set the FPS limitation to unlimited everything is normal. Can there be a problem with the graphics card?

With my old 60hz monitor it was the same case

Do you have 144 FPS or less?

YES throughout

Wouldn't know why it could happen. Just switch back to unlimited.

Yeah thanks.