nginx ip_hash loadbalancing issue

Hello Fellas,

We are using 2 nginx servers for both proxy and load balancer in our environment.
Both two nginx are running in different places. Lets say nginx1 and nginx2
Nginx1 is accepting traffic and simply passing the traffic to nginx2
nginx2 is using ip_hash for loadbalancing and distributing the traffic our application servers.
Problem here is, all the traffic coming from nginx2 distributes to one specific application server. It is probably hashing one IP(nginx1) internally.
I hope I clearly define my problem here and also you have an idea about that.

Thanks for your help in advance.

Burak