A company has an Azure virtual network with a subnet that contains virtual machines. They have deployed Azure Firewall in a hub VNet and peered the spoke VNet to the hub. They have configured a route table on the spoke subnet with a default route (0.0.0.0/0) pointing to the Azure Firewall's private IP as the next hop. However, traffic from the VMs is still going directly to the internet. What is the most likely cause?