Make sure that you have modified
AmiTCP:db/telnetddevice-conf properly:
23 2 255.255.255.255
Port - nr of nodes - and 255's
I'm not hundred percent sure about the file-name.
It could be telnetd.device-conf. Just try some versions.
And shut off all telnet-crap in AmiTCP if I recall correctly.
You use the telnetd.device and not the internal AmiTCP
daemon.