Weird aerodynamic force on parts

[Briso]

Hello. I'm just starting to model, so I'm sorry for the banal mistakes if they have a place to be. My problem is that the part (fuel tank) that I made .... It doesn't work properly. The aerodynamic effects on it are not the same as on all other parts. As you can see in the screenshots, they are twisted in a spiral somewhere under 45 degrees. Used by Unity 2019.2. 2f1, the latest version of Part Tools and TextMesh Pro Release 1.0.56. Everything was done according to the guide that is fixed in this branch. In Blender, I did the standard manipulations. Created a cylinder of certain dimensions. Smoothed it out and applied the Edge Split modifier. That's all. What can cause such strange things to happen ? 

[Fundati]

From what I understand, modifiers applied in Blender do not translate out, so that might be your issue.