Hi!
You could try to disable distance field lighting on your landscapes.
Select all your landscapes, Then in the details panel search for “Affect distance field lighting”
That will disable lumen on your landscapes. Let me know if that helped 
Hi!
You could try to disable distance field lighting on your landscapes.
Select all your landscapes, Then in the details panel search for “Affect distance field lighting”
That will disable lumen on your landscapes. Let me know if that helped