Question about Amazon Canada “Tax Invoices”.

We are a US based company that is registered with a GST/HST number with the Canadian government. When we view our “Tax Invoices” in the reports sections of Amazon Seller, it lists the fees we’ve paid Amazon, but no amounts are listed under the “Federal Tax” section. Does this mean? Does this mean that Amazon is or is not collecting GST/HST on our behalf? Any advice is much appreciated.