Hi Konsta Kallama,
Thank you for reaching out on Microsoft Q&A!
So, for my understanding: it takes a long time for the webhook request to receive a response? Could it be that the action simply timed out, and did not retry but send a "unsubscribe" to the endpoint, because of this timeout?
If so, can you make sure the webhook receive responds quickly enough for the webhook to process is, as is the idea with webhooks. Then it should continue without error.
Please click “Accept answer” if you find this helpful. Feel free to drop additional queries in the comments below!
Kind regards,
Sonny