POA-92597 pem.addSubdomain: provide_hosting=0 argument does not work
ObtainingHotfix can be downloaded here.
Use pa_updates_installer (https://kb.cloudblue.com/en/111323) to install this hotfix. Also this hotfix will be installed automatically during upgrade to OA 5.5.9 via pa_updates_installer. To install hotfix manually obtain its distributive from the link above and follow instructions found in file UPDATE.txt of distributive.