BAD PERFORMANCE AFTER ENABLED LANDSCAPE NANITE

Hello everyone,

I currently have a project on version 5.3 and I was getting 70-80FPS on High Settings.

And for better performance, I activated Landscape Nanite. However, my performance got worse while I was waiting for it to improve, so I disabled Landscape Nanite. However, my old performance has disappeared, now I get 20-30FPS even at Low settings.

How can I fix this? Please help me.

Thanks everyone.