[GNC] How to find Bill that a Payment was applied to?

[Fran_3]

I've got a strange case here.
Assets: Current Assets: Checking Account shows a 12/10/18 Payment to Vendor XThe Split shows- Liabilities: Accounts Payable- Assets: Current Assets: Checking Account
The 12/10/18 Payment also shows in Accounts Payable with the same Split
But when I run a Vendor Report on Vendor X the 12/10/18 Payment does not show.
The Bill shows posted on 12/3/18 in the Vendor Report but when I View Bill it shows unpaid.
So I'm guessing I must have two Vendor X accounts and applied the 12/10/18 payment to the wrong one.... BUT when I look at Business > Vendor > Vendors Overview only one Vendor X is listed.
The Question: How can I find which Bill the 12/10/18 Payment was applied to?
Thanks for any help.
PS
a - I searched everywhere for a 2nd account named Vendor X but can not find it anywhere except in the List of Vendors
b  - I'm running v3.7 on Windows 10