Grass FPS drop UE4 to UE5

So a while back I created a landscape material in 4.27 and today I wanted to bring it over to a new 5.3 project I am going to be starting, so I upgraded the 4.27 project to 5.3 in order to migrate it. Now the issue is, in 4.27 I have an 8k landscape filled with grass and it gives me 95 fps, I open the project in 5.3 and the fps I am getting is 40.
A drop of 55 fps is massive when all I have done is upgraded to another engine.
I looked into it and I implemented some things that people suggest like changing from lumen to screenspace etc. I managed to get the fps up to 60.
60 fps is still nowhere near 95.
How the heck is UE5 meant to be better when it’s wrecking my grass performance with me not doing anything different.
Does anyone know why this drop is happening? some setting somewhere that is defaulted to on in UE5 which is off in UE4?

This is almost certainly due to the default shadow map method being Virtual Shadow Maps in UE5. Switch it to cascading shadow maps in project settings to improve performance.