Customer setup as "CU" in BAccount, but there is a record in Vendor table too?

EDITED for clarity.  

I’m not having a problem.  Everything is OK!  😀  But perhaps my knowledge of Acumatica is deficient!

I was wondering if anyone could shed light on this.  The sample data shows AACUSTOMER as a customer.  You can see this in the BAccount table as the type is “CU”.  Prior to 2021R2, there was no record in the Vendor table for this account.  Starting in 2021R2, this account is also showing in the Vendor table.

There is a record in the Customer table (obviously)

There is ALSO a record in the Vendor table:

Is this an “anomaly” in the sample database, or is there some way in Acumatica that a customer can be added to the Vendor table even though the BAccount Type is “CU” and not “VC”?

You cannot bring up AACUSTOMER in the Vendor screen even though there is a record in the Vendor table.  I’m sure it is because the Type in BAccount is “CU”.