Sorry, i set up a new forward and take the wrong field. Changed it to the external port (where i had it before), but still dont work.
Found the following in the Teltonika Wiki for not working port forward:
"your LAN device that you configure Port forwarding to must have its Default Gateway (GW) set to Teltonika router’s IP address, otherwise Port Forwarding will not work"
Maybe my failure is in the lan definition - where do i have to define the default gateway? (in a static route?)
Thanks for the help