Soap Messages Not Decrypted

Hello,

A little context, I'm viewing the packet capture of a web service call, and the web service uses SSL. Service request/response is standard SOAP message.

Question is, why is it that when I add my key file to Wireshark(via Preferences --> SSL Protocol, which is a .p12 with both the private and public keys) that when I choose to "Follow SSL Stream" I can see the Soap request decrypted, but the response is still encrypted? I had thought that by adding the key file I'd be able to see both decrypted.

Thanks, John