It would be hard to say without the specifics (the timestamp of when Webhook fired and so forth) but we did have an Incident with some webhooks recently in the last week, that caused some webhooks to not fire intermittently. It's resolved now and these hooks would have caught up.
Is someone else still experiencing this issue?
I have a webhook registered with topic products/update, and have been doing some tests updating one product - the webhook is firing inconsistently.
As there are no shopify webhook logs accessible I cannot check whether the webhook fired (quite bad - logs should be made accessible to developers), but I'm checking directly our server logs and no request is received, so I'm pretty confident that the issue is in shopify.
When updating the product we are changing title, description and price, nothing too complex.
Is there any limitation on the frequency on product updates allowed, or any other limitation we should be aware of? I'm just testing human behaviour (nothing automated, nothing too fast or high volume) where on the same product I change title, save, go back after few seconds and change it again. Almost certainly the second update will not trigger a webhook. If I then update a different product the webhook will trigger...