Make sure that UEM is configured correct and the configuration share and profile share are available and users have correct permissions.
See this guide for all information needed:
Also make sure to follow this guide to create the mandatory profile for Windows 10, it's the only supported way:
https://technet.microsoft.com/en-us/itpro/windows/manage/mandatory-user-profile
If the UEM fileshare is not available at logon, the user will be logged off by default.
You can configure this behavior: what should happen if the fileshare is not available.
See this chapter in the installation guide for the available options and how to configure: