I just tried Logon plugin. I am able to register with SDK SP08 PL01 being on SMP3 sever SP07 PL02. I suggest you to upgrade SMP server and SDK to latest version and then try. I looked at xml file also. This is my finding which is same as mine (default one).
HTTP port:8080
HTTPS port:8081 (one way communication)
HTTPS Admin port: 8083 (for Admin cockpit and GW cockpit)
HTTPS Port: 8082 (mutual authentication)
I still wonder howcome you are able to execute https://smphost:8083
Nevertheless update this post once you are done with server and SDK upgrade.
Regards,
JK