Weird direction in 2D Mode

[hergen]

Hi there,

Your circle mesh is not nearly subdivided enough for it to be deformed in any meaningful way. It only has 5 large triangles at the center, and a lot of small tris at the edges. You will want to use much more homogeneous, denser topology so that it can deform properly.

Thank you for your reply!

But I think my problem originates from the normals. It works fine for the unity primitive plane. 
I analyzed the differences and found out that the normals are messed up.
Here are some screenshots from the two blueprints:

https://imgur.com/a/yZgepwt

I have tried to change the normals of the mesh manually, but it didn't work.

Is there a way to flip the normals (in blueprint mode)?
Thank you in advance