Config the Gerrit Trigger plugin on jenkins based on the article https://wiki.jenkins-ci.org/display/JENKINS/Gerrit+Trigger for the first time.
After input the connection setting information, press Test Connection, and the result shows Success.
But The connection could not be established. Error Message: The connection could not be established! Check your settings and the Gerrit server.
Please look at the screenshot.
Same setup was working fine with another test jenkins server.