It might impact you if you are sending long message size that exceeds 64 K. i believe getting on employ details may not be that big. However you can increase the outgoing message size in WCF service.
I still feel it's not related to any of these issues. When you are getting response from other application, it should work everwhere unless you make some mistake in the way you are consuming the service.
I have tried a sample in my machine with your scenario, everything works seamlessly without any issue. not sure why its not working for you.
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