Miroslav Baev on X: "Quick Blender Tip: To fix the weird shading in your cloth caused by wrong triangulation, in Blender you can set your triangulate modifier to "Longest Diagonal" which works
Triangulate (Modifier,remesh etc) (Mesh tesselation) - User Feedback - Developer Forum
Triangulate modifier: triangulate ngons only; 'Quad Method NONE' - User Feedback - Developer Forum