Virtualised Domain Controllers Replication Issues

I noticed virtualised domain controllers often have issues replicating new settings in Group Policy Objects. This warning message was also observed:

Error: 9036 (Paused for backup or restore)

After reading this Technet article on backing up virtual domain controller, I realised the cause was due to the snapshot back at Hyper-V level. The only supported backup method is running the backup job at the guest VM level. Since then, I've stopped backing up domain controllers at Hyper-V host level and disabled the backup integration services at VM configuration.