Secure Boot Test Package not working

[forceshutdown]

Hey Guys

I am trying to implement SecureBoot for my DragonBoard 410c. I am following this Guide and currently I have a Problem just with a test Build
https://docs.microsoft.com/en-us/windows/iot-core/secure-your-device/securebootandbitlocker

I am just using the Test Certificates and no additional Config to the XML. The Packet builds and I can flush it with the FFU. Windows boots up and enables Secure Boot. (It ist enabled in the UEFI Menu of the Dragonboard) but as soon as I restart the device, it does no longer boot windows.

I enabled RPMB and cleared the Keys before Flashing. Are there additional steps for a test deployment? I know that I need my own OEM Keys for Retail but I want to run test first.

QCDB_settings.txt

[xuliujian]

It seems that the Test OEM certificate is expired. I imported the OEM_Root_CA.pfx into my PC, and checked the Expiration Date, it is 4/10/2018.