Unable to plan Ansible tasks with large inventories in Satellite

Issue

• Planning an Ansible task with large inventories fails
• Only a multiple of a hundred sub-tasks are successfully scheduled (100, 200, ...) and the rest end in N/A status
• undefined method `wait' for nil:NilClass (NoMethodError) error message is found in /var/log/foreman/production.log
• The following conditions are met:
  • A large inventory is used
  • Multiple dynflow worker processes are used
  • Concurrency control is implemented