Regiiko:
It is connected to port 2, the ONT status light for port 2 is blinking green.
I suspect there may be a provisioning problem (but there is no information presented to support that other than it doesn't work). Below are some pictures that might help confirm what you already seem to know. In the first picture I have a type 400 ONT, with the connection as untagged PPPoE on port 1.

The data section shows that port 1 has negiotiated at 1Gbps full duplex (the cable is probably good on port 1).

Otherwise you might need to test using a PC (as indicated above) and/or packet level capture



