While processing the reimbursement, it appears that when the system is failing on the Dual Write side to create a one-time vendor. Regular Vendor Creation process is in tact, and the Vendor is created in CE without any issues using the same setup elements as a one-time vendor. We have a development environment connected to the CE instance where the issue is reproducible and can be debugged. See attached errors.

We've nailed it down to the validation during the customer update. It's creating the vendor and setting it on the customer. During the customer update it fails to find the vendor. More likely than not, it's happening in the same transaction and the customer update happens before the Vendor is committed.

The work around is to create the vendor manually and set it on the Customer. We tried this in DEV05 and it worked.