Webhooks will be automatically removed if they consistently fail (more😞
Shopify has implemented a five second timeout period and a retry period for subscriptions. Shopify waits five seconds for a response to each request to a webhook. If there is no response, or an error is returned, then Shopify retries the connection 19 times over the next 48 hours. If there are 19 consecutive failures, then the webhook subscription is deleted. A warning that the subscription will be deleted is sent to the app's emergency developer email address.