Accessing service in different namespace

Trying to scale a deployment using custom metric from api response, implmenting using keda:

I see this error:
Normal KEDAScalersStarted 15m keda-operator Started scalers watch
Normal ScaledObjectReady 15m keda-operator ScaledObject is ready for scaling
Warning KEDAScalerFailed 10m (x12 over 15m) keda-operator error requesting metrics endpoint: Get “http://integrations-service.default.svc.cluster.local:8772/v1/metrics/total-messages”: dial tcp: lookup integrations-service.default.svc.cluster.local on 172.20.0.10:53: no such host

integrations-service is in default namespace, integrations-service.default.svc.cluster.local is supposed to resolve a service in different namespace, but is not working as expected. How can I debug this?

Cluster information:

Kubernetes version: 1.24
Cloud being used: AWS
Installation method: AWS default setup
Host OS: linux
CNI and version:
CRI and version:
coredns version: v1.8.7-eksbuild.7
keda version: Package keda · GitHub

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