Azure AD Hybrid Join

Question

Hello

I already has all my pc windows 10 devices registerd to my Azure AD and i want to convert it to Azure Hybrid AD join.

my windows 10 1909

I have follow all instructions and i configure my ADConnect and i tried my pilot with 30 Machines and i foind only 5 machines has been converted from Azure register to Azure ad hybrid join.

I tried to monitor the failed machines and i found the below:

event 304:
Autimatic: registeration failed at join phase
Exit code: unknown HRsult error code 0x801c03f2

Error : 307
registration failed to lockup the resgistartion service information from active directory
Exit code:HResult error code: 0X801C001D

Answer 1

HAADJ requires connectivity to an on-prem domain controller.

Also, have you reviewed https://learn.microsoft.com/en-us/azure/active-directory/devices/troubleshoot-hybrid-join-windows-current?