I’m going to add both Bevel and Subdivision modifiers on this mesh, and I can make sure the vertexs of the both sides is totally same. So, the result should also be totally same after I add the modifiers. That’s what I need.
However, I got an asymmetric result on the left side (as you are looking in the picture). It has a raised corner.
As you just said, I have created this mesh many many times, and always got the similar result. And I have switch to the Wireframe mode to check, the both sides are totally same. This issue really desperate me!
I can’t tell from the image.
If you modeled one side and then replicated it to make the other side, there might be a Face Normal flipped problem.
Or there could be modeling mistakes.
if both sides are really symmetric and after beveleing the aren’t then you might check the normals by (the circle/disc icon on the top right) Viewport Overlays → Face Orientation and then everything should be blue. If not recompute normals…