Unity 2022.3.11f1 LOD.computeLod taking performance

Hi!
My unity project keeps having a low FPS, and when i check the profiler it says that LOD.computeLod takes a lot of performance, and also Shadows.CullshadowCasterIsWithoutUmbra uses a lot.
i searched up on the internet but there are just nothing about it. does anyone know how to fix this?
thank you!