Emin. I do hope to find you well...

When you active features like WAF (also when you make someting which request payload reading) on the NetScaler, it need to "read/check" the payload contents, so that it will request the server without any compression and, so that, to provide an acceptable performace, it could use http compression and Chunked Tranfers. It you disable HTTP compression on the "Service Group/Service" you get an non chunked response (I'm not sure if this behavior occurs in the all situations, unfortunately, but you can try...).

But, you must mind the compression will be disabled and you will get a lot a traffic on large responses payloads... I tried to post a image, I'm a rookie here and I'm not good with forums at all... :)

On the NetScaler... Load Balancing/Virtual Server ServiceGroup Binding/Load Balancing Service Group

Disable Service Group/Service Compression

Another option, this one outside of Netscaler, you could use the HTTP header Cache-Control: public, no-transform to prevent any modifications by any proxy...

Cache-Control: public, no-transform Disable HTTP Compression on the ServiceGroup

I hope to help you...

Ricardo