Some big static meshes stops rendering halfway in mobile preview

While beginning to work on a mobile version of our game I noticed that suddenly some of the paths you race on turns invisible like they just stopped rendering halfway. The paths are originally created from splines and then combined. This only happens in the mobile preview.

This is what it looks like:

The collision is still working, I just can’t see some of the mesh. It’s not a problem with the material since it’s the same with the default gray.

It’s kind off a big mesh, but not that extreme in terms of verts/triangles (the biggest one with this problem is around 150k tris).

For now I’ve found a workaround of exporting the mesh, and then reexport it from maya as an .obj instead. This makes the whole mesh visible again, but it comes with other problems so it’s something i rather not do to all my paths. It’s not problems with normals/wrong sided faces or something like that.

Is there some kind of limitation on meshes to work correctly in the mobile preview or am I doing something else wrong?