Route 53 -> API GW -> CloudMap -> ELB Internal Server Error

I have a setup with where I have the following:

• Custom domain name for HTTP API GW
• HTTP API GW with ANY proxy route. This route has a VPC LINK integration with CloudMap
• CloudMap Namespace with 1 Service. Under this service there are two registered ALBs with the correct internal DNS Alias from what I see
• Each ALB forwards to unique ECS Service

Requests to my custom domain name return a "Internal Server Error". I tried the following setup which works fine to test that the API GW, VPC, VPC Link, and ALBs were configured appropriately

• Custom domain name for HTTP API GW
• HTTP API GW with ANY proxy route. This route has a VPC LINK integration with ALB
• Each ALB forwards to unique ECS Service

Is this cloudmap setup a viable setup? I enabled cloudTrail logs on my setup and see API GW making DiscoverInstances requests, but responseElements in that log is null. When I try a discover instances requests from the AWS CLI, I do see the 2 ALBs show up as Service Instances. I see no requests hitting my load balancers in the cloud map setup (from cloudwatch metrics) so it does not look like the requests make it there