But how does it look in Blender when you are out of Edit mode?
Also, after you’ve got everything put together the way you want it, click A to select all (vertices, edges, sides, it doesn’t matter) then in Edit mode go to Mesh>Normals>Reset vectors to ‘fix’ many of the twists you get when moving faces, edges and vertices around.
Is the mesh mostly flat? You seem to have a LOT of unneeded tris for such a small item.
this will only happen when you export it with fbx but if you import it as OBJ and turn off shadows it won’t look weird
it’s tedious to do multiple parts though imo
I figured something out that works for me, you have to use Import 3D in Roblox. And once you are about to import you have to check Invert Negative Faces.