Cashier / Stripe Webhooks - Working?

I have set up Stripe Webhooks as per the 5.1 documentation and I have added a bit of middleware so that I can log the web hook payloads that are arriving to a table.

All is working well and response 200 codes are being returned to Stripe when a web hook arrives. I can see all the payloads in my log table.

But no matter what I try, I cannot get Cashier to make changes to the billable model for example when the subscription is cancelled. The web hook arrives, Cashier returns 200 to Stripe but nothing changes in the billable model and the subscription remains live. The stripe_active flag remains as 1 and the subscription_ends_at field never, ever changes.

Kinda tearing my hair out here. Has anyone else seen this?