Why does my webhook get called twice during app subscription plan changes?

I have created an APP_SUBSCRIPTIONS_UPDATE webhook. When I install an app and upgrade the first plan to the second plan, the webhook is run only 1 time. But after that when I upgrade or downgrade the app subscription plan, the webhook is run twice on each plan change event. here is shopify doc link and webhook log

When the product is added in the shopify dashboard, we are getting add, update both webhooks for the same product.

When we add the product we should get only add webhook call.

currently we are getting products/create, products/update both webhook, due to that product adding multiple times our end, let us know is there any reason triggering both webhooks ?