Sorry for the lack of data related to the configuration, I was in a hurry!
So, both instances are on same region : us-central1 for Cloud Run and us-central1-f for Cloud SQL. (I assume these are the same). I use :postgrex, "0.15.13" & :ecto, "3.7.1" and connect to database through socket socket_dir: System.get_env("POSTGRESQL_SOCKET"). Instance IP assignment is set to Public IP. Tell me if you need more information about this.
