The `stop!` method sets `@stopped=true`. So once the config manager is stopped (via `stop!`), it can never be started again. https://github.com/optimizely/ruby-sdk/blob/44d585926c259f56d09dc5c25dd1e5f1551414fd/lib/optimizely/config_manager/http_project_config_manager.rb#L92-L95