How to handle expired subscription with billing error that can be renewed?

Hello there!

I’ve stumbled upon a quite odd behavior while managing permissions of a subscriber. I give promotional entitlements based on some special users and I handle it by checking whether the subscription is expired or not.

In the case I’ve observed, after receiving a webhook containing information of a BILLING_ISSUE event, my routine waited for it to expire to check if the subscription was still active, and it wasn’t, so I revoked the promotional entitlement.

However, the user latter came to complain, and when I checked their profile on RevenueCat’s dashboard, their subscription was active, but without any events on new subscription or renewals. I immediately returned their promotional entitlement, but I was lost with no information to why they were still active.

I’ve used the expiration_at_ms to wait after it to check through the API if the subscription was active.

Here is the webhook I received:

{
  "api_version": "1.0",
  "event": {
    "aliases": [
      "..."
    ],
    "app_id": "...",
    "app_user_id": "...",
    "currency": "BRL",
    "entitlement_id": null,
    "entitlement_ids": [
      "..."
    ],
    "environment": "PRODUCTION",
    "event_timestamp_ms": 1629289127246,
    "expiration_at_ms": 1629375526420,
    "grace_period_expiration_at_ms": 1629893059552,
    "id": "...",
    "is_family_share": false,
    "original_app_user_id": "...",
    "original_transaction_id": "...",
    "period_type": "NORMAL",
    "presented_offering_id": null,
    "price": 0,
    "price_in_purchased_currency": 0,
    "product_id": "...",
    "purchased_at_ms": 1629288259552,
    "store": "PLAY_STORE",
    "subscriber_attributes": {...},
    "takehome_percentage": 0.85,
    "transaction_id": "...",
    "type": "BILLING_ISSUE"
  }
}