Segment error in visualization of a complex Momentum model

I simulated a coplanar curved signal divider (without air bridge) in Momentum, and I'm sure the meshing is fine enough to capture all the details. But after running the simulation, it gave very odd visualization. I tried both strip and slot mode, but none of it worked. The attached images are saved from the program. Red outlines belong to the design, which I imported from AutoCAD design.

Does anybody know about such error. Thanks!

Share the project to enable us in better understanding

The two design files belong to a huge project folder, so I tried to start a new project and use "copy design" to copy those two .dsn files to the new project. But it doesn't import the layout and substrate settings, and I don't know where I can find the finished simulation data so that people don't have to wait for a couple of hours to see the result. Could you please tell me which files should I look for and I'll do this ASAP? Thank you very much!