Webhooks created by another user

I had created a asana user and using its access token I have created some webhooks. Now, for some reason, we needed to change the user multiple time.
Now, one of the users were deleted and I wanted to check all the tasks which do not have a webhook. But in the get webhook API, I am only able to see webhooks created by the last user(whose access token was provided) but I am receiving webhooks for tasks for which webhook count are showing as zero