When the Jenkins Artifactory Plugin deploys the build-info to Artifactory, it opens a connection to Artifactory; at this time Artifactory performs some processes relevant to the deployment. If you are experiencing deployment timeouts, it might be because at this point Artifactory is deleting old builds as configured in the Jenkins job's build retention. While this processing is ongoing no data is transferred back from Artifactory to Jenkins, so when there are many builds to delete the process may take a long time to complete; longer than the configured connection-timeout in Jenkins.
In order to resolve this timeout issue, prior to running the build with the build retention enabled, you can manually delete the old builds using the Delete Builds REST query.
If you do not want to manually delete builds, you can try to increase the connection timeout in the Jenkins UI ? Manage Jenkins ? Configure System ? Artifactory ? Advanced ? Connection Timeout.