ZBrush FBX trouble

I have simplified my model in RC and exported it as a mesh.

In ZBrush, it looks like this:

You can clearly see strange patches.

It has only happened right now, not with other models, but it happens each time I import this model.

My import settings look like this:

The UVs in ZBrush look like this:

I wonder what is happening here.

These are my export settings:

In Autodesk FBX Reviewer, it looks fine.

Has anybody had the same experience already?

Ok, I found a solution:

When I select “Texture format” JPG instead of BMP, it appears fine in ZBrush.