Note: If there is no AWSELB cookie in the response, then there is no stickiness between the client and the backend instance.

2.    If the load balancer inserts an AWSELB cookie, be sure that the client sends this cookie in subsequent requests. If the client fails to include the AWSELB cookie, then stickiness won't work. To verify that the client sends the AWSELB cookie, take a packet capture on the client or use the browser’s web-debugging tools to retrieve the cookie information in the request header.

3.    Check the duration configured on the load balancer. If the cookie expiration period has passed, client sessions no longer stick to the registered instance until a new cookie is issued by the load balancer.

4.    If your request is passing through multiple load balancers, verify that stickiness is enabled on only one load balancer. If more than one load balancer inserts a cookie, it replaces the original cookie and stickiness fails.