Ambient Occlusion with flipped sprites

I’m currently using the Ambient Occlusion from Unity’s Post Processing Stack in a 2D game.

AO works fine on normal sprites 121035-right.png.
(I flip the sprites with localScale.x *= -1. I’ve also tried using the flipX option of SpriteRenderer but no luck :(.)

The shader I’m using is the Pixel Lit sprite shader from Unity Sprite Uber Shader. Lighting, shadows even DOF seem fine, only AO.

Any suggestions?
Many thanks in advance!

I actually just found out a workaround to this!
The Multi-Scale Volumetric AO from Unity’s latest Post Processing Stack v2 works perfectly with sprites!