Welcome to the community!
Whether your phone automatcially updates the SMR would depend on your phone's settings. You can check to see if your phone as already updated via Settings --> About Phone --> Software Information. That page should list the Android Security Patch Level. If your Security Patch Level shows September 1, 2021, then it would have automatically updated with the latest SMR for that device. As far as I am aware, the S9 would receive Quarterly updates for the moment (see here).
If your Security Patch Level shows an earlier date, you might consider downloading and installing the update manually: Settings --> Software Update --> Download and Install. If your device does not show the latest available update and the Update function shows your device is up-to-date, you should note that the updates are usually available in batches. Additionally, what version of the device do you have? You should also note that updates for non-Canadian versions of the device won't likely via Fido. You would need to search for the proper update for your phone verson.
Hope this helps 😀