Azure: App Service cannot connect to vnet-base VM

Bumped into unusual issue today:

I do have a SQL Reporting Services VM on one of my Azure Vnets. I also have several App Services (Web Applications ) connected to it. Normally when I set up VNet integration for App Service Azure creates a P2S SSL VPN and routes 10.0.0.0/8, 172.16.0.0/16 and 192.168.0.0/16 ranges to the tunnel. An everything works fine.

I created a new App Service and configured it for Vnet Integration. Surprisingly the app was not able to connect to SSRS.

I ran Kudu debug console and found tcpping from the App to SSRS failed.

It turned out during P2S VPN creation Azure for some reasons added only 10.10.0.0/16 qnd 10.20.0.0/16 (???) as the tunnel destination.

Resolution: I added IP address of my SSRS to the table and successfully connected to the Web Service of my SSRS. I guess that happened because I an using hub-and-spoke for my vnet. The only question why it was working before for other App Services