Deploying puppet modules from Satellite 6 fails with 'Could not retrieve catalog from remote server: Error 400 on SERVER: Duplicate declaration: Class[example::name] is already declared; cannot redeclare at /module/path/init.pp:34 on node my-client.com'

Issue

• Unable to deploy puppet module which has sub-modules in it, getting below error:

  Error: Could not retrieve catalog from remote server: Error 400 on SERVER: Duplicate declaration: Class[example::Linux] is already declared; cannot redeclare at /etc/puppet/environments/KT_Default_Organization_Lifecycle-env_conten-view_Content_70/modules/firewall/manifests/init.pp:34 on node my-client.com
  Warning: Not using cache on failed catalog
  Error: Could not retrieve catalog; skipping run