FATAL: Peer authentication failed for user - (PG::ConnectionBad)

Having a Strange Issue. Deploying a Rails 5 App on Ruby 2.3.1

With

config.eager_load = true #in production.rb

When I try starting Unicorn with

bundle exec unicorn -D -c /home/deploy/apps/cgrates_web_production/shared/config/unicorn.rb -E production

I get this error

FATAL:  Peer authentication failed for user "demo"  (PG::ConnectionBad)  #in unicorn.log

If I set

config.eager_load = false #in production.rb

everything works as expected. Unicorn Starts up and i can access the Application and perform CRUD Operations.

Any Help would be highly appreciated