There have been failures related to navigating through Subitems list:
https://travis-ci.org/github/ezsystems/ezplatform-admin-ui/jobs/725885518
https://travis-ci.com/github/ezsystems/ezplatform-page-builder/jobs/376717537
https://travis-ci.org/github/ezsystems/ezplatform/jobs/720511660
https://travis-ci.org/github/ezsystems/ezplatform/jobs/720324005

Looks like we're not able to find the Content Item we're looking for. We should investigate what could be the cause and how to solve it.

Possibly related:
https://jira.ez.no/browse/EZP-31283