I suggest you contact our Technical Support team for assistance with this issue. They can pull up your account information and investigate why there's another Checking account generated after you enrolled in the Payroll Core service.
You can keep this article as a reference: Contact Payroll Support. It includes their hours of operation, so you know they're available when you contact us.
Let me if you have other questions about the Payroll Core service. Post a comment below, and I'll get back to you.