'verify your account' emails from google cloud platform

We keep receiving emails from CloudPlatform-noreply@google.com asking us to verify "your google cloud account" followed by a number. But clicking on the Verify button leads to a "not found" page on google cloud console. Clicking on the "Support" link at the bottom of the email, I came to the link for "interactive billing assistant" at

https://cloud.google.com/support/billing

which led to

https://apps.google.com/supportwidget/helphome?product_name=Cloud+Platform&product_context=billing/chat&hl=en_US

That "AI assistant" suggested that this may be a message to verify the billing account payment method. I see that a billing account with payment method had been created in the past, but we're not currently using any paid services. 

The accounts dept verified the payment method with credit card, but we still get these messages. Probably due to some other account which was used to create google assistant action? Perhaps.