Razer keyboard backlight always flashes in fortnite - how can I turn it off without permanently switching off my backlight?

My question is about a razer chroma ornata keyboard. When I use the PC normally, the keyboard backlight works normally, but as soon as I start fortnite it flashes continuously. Can someone tell me why this is, or how I can turn it off without turning off the backlight completely?
I would be happy if anyone can help me, have tried everything that came to my mind via Razer synapse, but unfortunately without success…

Start Razer synapse, then press "connect" in the bar and switch Fortnite to off