Windows Server 2019 has been started to be supported since Asigra DS-Client v14.1 hotfix 8:
Windows DS-Client Hotfix 8 (14.1.0.8) or later:
- Windows Server 2019 (BMR file system)
- Microsoft Exchange Server 2019
- Microsoft Hyper-V Server 2019
- Microsoft Outlook 2019
- Microsoft SharePoint Server 2019