I have a simple pipeline job:

pipeline {

    agent {
        label 'master'
    }

    triggers {
        cron('* * * * *')
    }

    stages {
        stage('main') {
            steps {
                sh "echo foo"
            }
        }
    }

}

I create the pipeline project via the Jenkins UI. I expect that I will see cron build triggers in the UI as a result, but in fact none appear after initial project creation. Only after I have manually triggered a build of the pipeline does the expected cron build trigger appear and begin working. It seems like the build trigger should be present immediately after saving the job with the pipeline script shown above.