I've looked at other questions surrounding this problem and tried to fix it, but none of them work. This includes removing armature modifier, applying pose as rest pose, then adding it back and reparenting. I've tried keeping the armature modifier and applying pose as rest pose, still doesn't work. I know there's a way to fix this, because I figured it out in the past but now I can't remember how I did it! xD
Thank you in advance.