Counterfeit Without a Test Buy warning even though I never sold that product on Amazon

Hello All,

We've recently received this warning from Amazon: Counterfeit Without a Test Buy - For this product: ASIN: B09XC5GG83

While this product is part of our product inventory, we've never sold even one unit of it through Amazon. What's even weirder is the complains seems to be coming from a random gmail account instead of a company.

So my first question is how is it possible to receive this kind of warning from some random people in the first place and how is it possible to receive this warning for a product we never sold through Amazon?

Second question, how do we deal with this, as Amazon seems to reject any kind of appeal with automated responses rather than looks into it?

Many thanks in advance for anyone's time who'd be willing to help us with this.