ApplePay q: Transaction receipt shows my cc last four digits?

I used ApplePay to purchase groceries via a shopping service app, but the transaction in my iPhone's Wallet doesn't say ApplePay. (My transactions that were in-person at a store show ApplePay as I expect.)

Email receipt from the shopping service lists payment as ApplePay <nnnn>, where <nnnn> is the last four digits of my credit card - NOT my ApplePay number.

Has anyone seen this before?

Perhaps this shopping service is still charging my credit card directly? If ApplePay transactions require vendors to pay, this might make sense (and if that's true, I'll report them for it.)

Thanks in advance for your help.