Colision changes after turning on Nanite

There is a large static mesh that will be used as terrain. With nanite turned off, the collision grid is correct and works well. When Nanite is turned on, it is greatly simplified and becomes unusable. How to solve this problem?

Ideally, I would like to add another mesh as a collision, which will have a more sparse mesh, but how to cure collisions at least at the initial level?