Time server problem building a V570 VxRail cluster at configuration Task(18 / 80)

Building a V570 VxRail cluster, the validation step is OK. After the validation step I started the deployment and  ran into a problem at configuration Task(18 / 80). The marvin.log file contains time server error messages. As NTP server I tried both a local Windows Server 2019 AD domain controller and pool.ntp.org. All resulted in the same error. Any idea what to look for?