Persistent SSL/TLS connections for SOAP web service load testing?

Greetings all,

I have been endeavoring to set up a load test for a Mutual-TLS-enabled SOAP web service. My client certificate is set up and functioning as expected. I created a brand new Test Suite, with a single Test Case, which contains 3 steps (some Groovy and two SOAP calls) and a single Test Case with a single Load Test with all the defaults (5 threads, 60 seconds, etc.)

I'm getting absolutely awful performance, mainly because SoapUI keeps setting up and tearing down a brand new TLS connection for each thread & iteration of the Test Case (incuring the overhead of a TLS handshake each and every time). 

I've checked "Maintain HTTP Session" at the Test Case level, but seemingly with no effect.

Any thoughts on what the issue might be?

Regards,

Chris