"apple.com/us" identified
apple.com/us is an Apple Support purchase.
I had an unrecognized charge from "apple.com/us". This didn't match any of my purchases, so I chatted with Apple support. The *third* advisor finally found it: it was a charge for a replacement AirPod. The charge doesn't show on your Apple ID account, and even when I found the email "receipt" and the online support history there was no indication of the amount. So, if you have a charge from "apple.com/us" look for service requests/purchases.