RESOLUTION
Since 2.2.0 versions Expand CP uses it's own web server named "sw-cp-server". This is actually Light-HTTPd server and it's configuration directory is /etc/sw-cp-server/.To change the default Expand port for Plesk Expand control panel, please edit it's web server configuration file /etc/sw-cp-server/applications.d/01_expand.conf and replace the default port 8442 with yours in the string:
$SERVER["socket"] == ":8442" {
After that it is necessary to restart the Expand control panel:
# /etc/init.d/sw-cp-server restart