I've gone through all the troubleshooting steps they provide here. My endpoint is accessible, SSL passes the tests. Webhooks work when I'm testing on my local environment using ngrok but it does not work on staging and production servers hosted on AWS and managed on Laravel Forge. The webhooks post request simply does not hit the server.
I contacted the QuickBooks support about this several times. Their response is, they get a timeout - StatusCode 41 when they post the notification to my endpoint. And they say that the network is restricting traffic in some way. Also contacted forge support and they said they won't help with application-related issues.
I tried disabling the firewall with UFW, reviewed all the logs but I don't see any way how the server is restricting the traffic. I retried several times changing the webhooks URL on sandbox and no luck.
Any help would be greatly appreciated.,
edit: SSL is valid, csrf is turned off, url is publicly accessible, a curl request from another server goes through fine, nothing in logs.
RESOLVED Edit
Webhooks started working again on their own after a recent update they did on the Webhooks functionality. While I'm glad it's working finally, I don't appreciate all the time I wasted debugging this.