Why Google Customer Ratings Badge Show 0.0 Ratings?

Google needs 100 reviews in total in last 12 months, which can be collected from other sources(not just SMPS Google Customer Reviews) as well.

Once the number of reviews crosses 100 in the last 12 months, ratings will be available on Badge. 

If you want to avoid displaying 0.0 ratings on Google Customer Reviews Badge, go to App Settings, and turn off the badge.