I see problems similar to this with a lot of people starting out in Maya. It's often a result of extruding border edges and not paying attention to the direction that the face normals are pointed, resulting in meshes that are half correct, and half inside out. A common mistake for beginners is to extrude and move an edge,…
Switched to legacy and nothing changed, In object mode those lines does not appear, but they mess things when I try to do a selection with double click X_X