Membership not updating subscription end date

I am unable to get my Membership Pro plugin to renew my subscribers.

The payments are coming back to the site – I can see them on the “Transactions” screen on the Gateway - but the expiration date is not updated.

It should also be noted that all of these users were migrated from another subscription system. They are all configured with the Paypal Express gateway.

Happy to provide admin info upon request. if that means a speedier resolution.