No specific message is logged in Xen agent log indicating that it is unable to monitor Storefront server due to Powershell ExecutionPolicy setting.
Known Enhancement request referenced by Tracking ID VFOG-12368.
Enhancement Request VFOG-12368 has been submitted to Development for a fix in a future release.
Please check the release notes of latest version of XenDesktop cartridge to determine which bug fixes have been included in this release.
Please verify that ExecutionPolicy is set to Unrestricted on target Storefront server/s for successful monitoring.