AWS NLB Ingress Gateways error with multiple clusters


I have deployed 2 K8S multi-AZs clusters in AWS with kubeadm (same account, same region, same AZs).
I have successfully configured Istio Ingress with AWS NLB for the first one but when trying to do the same for the second one, the NLB is not created properly (the resources is created in AWS but it does not have any listeners nor target groups).

As mentionned here there was a bug preventing to have several clusters in the same AZ but this bug seems to be fixed as seen here :

To check that the problem came from NLB, I tried to configure the second Istio Ingress with an ALB instead and it worked well.

Can you confirm me that my problem is related to this “old” bug ?
And how can I investigate such a issue if not ?

Thank you