When using the Spotify model, there are many different squads, who each own their own product. Now as far as I understand, these products could be interdependant (like services). One way to manage this in Jira (or similar) could be to create a project for each squad (so each squad has their own backlog).

If a bug occurs during a black box test, it might not be immediately clear, which service (product) is the cause of the bug and therefore which backlog it goes to. This leads me to my question:

Where do you report a bug, before you know what service (product) it relates to?

Example:

When placing an order in a webshop, there are three different services involved:

• Ordering service
• Inventory managment service (stock)
• Payment service

A bug occur during a black box test, while trying to place an order. It's not immediately clear, what is causing the bug. In which squads backlog should the bug be (initially) created?