For new installs or upgrades the following need to complete before DLPe starts reporting the most accurate information:
1. Agent install
2. System Reboot
3. User Login
4. First ASCI after reboot
5. Enforce policy after the ASCI
DLPe gets a new policy from ePO as part of step 4. The policy gets enforced as part of step 5.
This is needed just one time for the very first initialization.
Please explain to me, why ePO agent can't get full properties from DLP Agent to ePO when no one is logged-in on this machine?
DLPe Agent runs only when a user is logged on. What you are seeing is expected and not a bug.