We have registered all three webhooks of inventory item (inventory_items/delete, inventory_items/update, inventory_items/create) but unable to receive any notification from Shopify side. We changed cost, harmonized_system_code, country_code_of_origin from shopify UI but didn't receive any webhook related to inventory item. We tried to create new variants as well but still no luck.
We verified webhooks registration status using postman API and found webhooks are successfully registered for inventory_items endpoints.
Screenshot with shop and webhook registration details: