Sharepoint is not triggering my webhook Function App. The app is registered on my list and I get a response when I access the URL via the browser.

Question

I've created a resource and function app, gave it read permissions, registered the webhook in the sharepoint list I want it to work in but I'm not getting anything in the monitor log. When I access the registered URL directly it shows up in the log correctly, so the webhook is active and operational. Any ideas what I'm missing here?

The validity is not an issue as I've set it at 5 months. Powershell shows me:
PS C:\Users\user> Write-Host "Webhook registered with ID: $($webhook.Id)"

Webhook registered with ID: 6b3c90be-c83a-8902-dega-a987bff0141a

How do I find out why sharepoint doesn't trigger the webhook?