Ah ha! I found a workaround. Later in the Communigate Docs it says:

"Set the Init SSL/TLS listener socket option to Ext to tell the Listener component that all connections coming to this socket are SSL/TLS secured, but that there is an external device implementing all SSL/TLS encryption/decryption operations. Connections coming to these ports are clear-text connections, but higher-level CommuniGate Pro components and protocols process these connections as if they come encrypted: clear-text Login operations are considered secure, STARTTLS operations are prohibited, etc."

So I changed it to "EXT" and it appears to be importing!  Thank you for figuring out the root cause!