Problems with mirror-based options

Hi, i noticed a problem with my mesh when i tried to apply mirrored shape keys. I didn’t work. So i checked my mesh but found nothing wrong. I cut it in half and mirrored it again. I applied location scale and rotation, but nothing helps.
When I activate x mirror it doesn’t work as well, although the vertices has exact the same location with one axes mirrored.
And when i activate mirror topology it gives me some strange issues.

In Maya i would try to delete history but i don’t know how to fix this problem in blender.
So now i deleted all of the stuff in my scene. The armature, the blend shapes the weight paints just to have the blank model.
Figure.blend (1.83 MB)

Hope someone can help me with this. I need to finish this for a project, but don’t wanna do the blend shapes for each side manually.
Thx and greetings.

You have both X Mirror and Topology Mirror enabled.

Use X Mirror and rorate the object so it mirror across the X axis or use the mirror modifier

Y is forward in Blender so your model is rotated the wrong way, the mirror options (except the mirror modifier) only support mirroring along the X axis. You can rotate the model in edit mode by selecting everything, pressing rotate, z, then -90.

After that you’ll see the model is a bit off center, you can move it in edit mode again and line it up with the green Y axis grid line, then select everything and do Snap to Symmetry (search with spacebar). Sometimes with more denser meshes it can snap to the wrong vertex, when that happens I use instead.

when that happens I use…/Mesh/Remirror instead.
Or just use the built in symmetrize option in the mesh menu

Symmetrize creates new geometry so shape keys can get messed up. Remirror just reorders the vertices so shape keys aren’t affected.

Man such an easy solution. -.-’ ty for help. And sry for such an obvious question.