Yours is absolutely an exception. I also have Google Fi, but I had to create a second Google account in order to get it.

I had Google Wallet years back. At one point while I was traveling, I lost my debit card and thankfully had my Google Wallet card as a backup. I was able to transfer money to the card from my checking account, though I only moved over what I needed for short periods of time. This resulted in multiple movements of money to my Google account, which in turn resulted in Google flagging this as suspicious and preventing that account from using Google to pay for anything (I couldn't even purchase via the Play Store even if I selected my non-Google debit/credit cards as payment methods). They asked for verification of who I am, and I supplied the correct documents to them multiple times. Each time I was told that those documents did not suffice with no explanation as to why they were not reauthorizing my account nor why the documents I sent them weren't up to their standards. Just "Nope, go away."

For some dumb reason I insisted on proceeding with signing up for Fi, and found it super easy to just create a new Google account specifically for that. I've been increasingly uneasy about the longevity of this account because of that experience and realize now that it was probably foolish to migrate my phone service to a company that had already fucked me, but c'est la vie.