Blender Animation: Mirroring Problem

[Player19273712 (vinf4z)]

1. What do you want to achieve? I’m trying to fix this mirroring issue in my blender rig.
2. What is the issue? This is how it looks like before mirroring:
   
   

and this is after mirroring:

3. What solutions have you tried so far? I tried looking into “Bone Roll” as well as rotating the bones, but it didn’t work

Any help is appreciated. Here’s the blender rig project:
RobloxianR6.blend (2.8 MB)