Intermittent issue with the App Subscription Approval flow

[Aditi_Maurya]

We’re encountering an intermittent issue with the App Subscription Approval flow.
Steps to reproduce

1. Open the Approve subscription page.
2. If no payment method is configured, click Go to billing settings.
3. Add a payment method (or simply navigate to the Billing Settings page).
4. Return to the Approve subscription page.
5. Click Approve.

Observed behavior
The issue occurs intermittently. Sometimes the approval succeeds, and sometimes it fails.
When it fails, the UI displays: “We were unable to approve this charge. Please try again.”

From our investigation, we observed that the BillingAppSubscriptionAccept GraphQL operation is occasionally sent with a null signature, resulting in an INVALID_VARIABLE error because the signature is required.
We also verified the subscription using the Admin GraphQL API after the failure and found that the subscription remains in the PENDING state, indicating that the approval never completes.
It appears that after navigating to Billing Settings and returning to the approval page, Shopify occasionally sends a null value for the required signature parameter. Since the issue is intermittent, we’re unable to determine what causes the signature to sometimes be missing.

We’ve attached screenshots of:

• The approval flow.

• The failing network request.

• The GraphQL error response.

• The subscription state after the failure.

  
  
  
  
  

  We have two paid apps on Shopify and facing the same issue on both.

[KyleG-Shopify]

Hey @Aditi_Maurya, thanks for reporting this. I’m looking in to it and will follow up with what I find.