I have an api that I am building and linking it to my nginx ingress controller to be used as a loadbalancer. My below yaml works when I change the namespace to default and I'm able to access the API no problem. When I change all the below to any other name space and install in that namespace, I get the error from ingress controller:

Service does not have any active Endpoint

so I thought that the nginx ingress controller (deployed in default namespace) was supposed to be able to see ingress in all namespaces. So is there something wrong with my deployment steps below?

---
apiVersion: v1
kind: Service
metadata:
  name: demoapi
  namespace: alex
spec:
  type: ClusterIP
  selector:
    app: demoapi
  ports:
    - protocol: TCP
      port: 80
      targetPort: 8080
      name: http

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: demoapi
  namespace: alex
  labels:
    app: demoapi
spec:
  replicas: 1
  selector:
    matchLabels:
      app: demoapi
  template:
    metadata:
      labels:
        app: demoapi
    spec:
      containers:
      - name: demoapi
        image: myrepo/demoapi:latest
        ports:
          - containerPort: 8080
        livenessProbe:
          failureThreshold: 3
          httpGet:
            path: /actuator/health
            port: 8080
          initialDelaySeconds: 15
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 3

        
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: nginx
    kubernetes.io/tls-acme: "true"
    nginx.ingress.kubernetes.io/proxy-buffer-size: 512k
    nginx.ingress.kubernetes.io/ssl-redirect: "false"
  name: demoapi
  namespace: alex
spec:
  rules:
    - host: mydomain.com
      http:
        paths:
          - backend:
              serviceName: demoapi
              servicePort: 80
            path: /api/v1/hello
  tls:
    - hosts:
        - mydomain.com
      secretName: mydomain-ssl-secret

I also checked nginx controller config - and it's set with default to watch all namespaces