Download Fails when a WAF policy Attached to F5 Silverline

Hi Team , Im facing a very weird issues here for one of the application as it fails to download when a WAF policy is attached to proxy. Following is how our infrastrcuture looks like.

 

Client -> F5 Silverline with WAF policy -> BIG IP LTM (ssl offloading/URI rewrites etc ) -> BIGIP LTM(Load balancer) -> Application VM.

 

With the above set up following are the scenarios.

 

1. With WAF policy & Fast network - Download success.

    

2. With WAF policy & Slow Network - Download Fails.

    

3. Without WAF policy & Slow Network - Download success

    

So here trying to figure out any posssible issues related to point no 3. Is there anything need to be considered from BIG IP LTM perspective ? I have explored almost everything and no luck so far with a policy attached and download works on slow networks.

 

If anyone came across this scenario , please pour some advises to me.

 

Many thanks In advance.

 

Jibin.