Why is the route advertisement to ingress sources not working?

After the route advertisement to Transit Gateway, Direct Link, or both is enabled for an ingress routing table, the traffic isn't working as expected even though the VPN gateway connection is up and running.

A route conflict might exist.

Follow the steps to resolve this issue:

1. Go to Interconnectivity > Transit Gateway and locate the transit gateway that connects to the VPC where the VPN gateway exists.
2. In the Routes section on its Details page, click Generate report to see whether a conflict exists. For example, routes might be overlapping.
3. Resolve the conflicted routes by adjusting address prefixes in VPC.