Did several downgrade to my older 2016 QC 35 version 1. Below option worked better.
Downgraded to 2.5.3 Reset the headphones
Upgraded to 3.0.3 by laptop and not app.
Reset the headphones.
Boom, Anc is back. I can now surely distinguish between Low and High ANC option. Still i can see a little lesser ANC than it was before the latest update. Fingures crossed to see a new Update from Bose.