I don’t believe I have a solve for your question, but related to it, here are 2 topics about this you might want to check out to see if you agree with:
[BUG] Shader code ‘viewdir’ and shadow/light rendering are inconsistent on right eye
I don’t believe I have a solve for your question, but related to it, here are 2 topics about this you might want to check out to see if you agree with:
[BUG] Shader code ‘viewdir’ and shadow/light rendering are inconsistent on right eye