Connectin pfsense directly to 1GBit ZTE ONT

Hi, I have my TIM (Italy) ONT installed (its a ZXHN F6005, which I think is also installed by OpenFibre in the UK). This is connected to a TIM router and them to a minipc machine that has pfsense installed. I believe the ZTE ONT can be directly connected to the WAN port of the pfSense machine by having pppoe set on the WAN interface. That way I can drop this intermediate TIM router which is simply sucking up energy. I tried setting a pppoe connection the pfsense machine by giving it userid and password but the connection never comes up. Strangely, even when leaving the WAN interface set to pppoe on pfsense and reconnecting it to the intermediate TIM router, the connection comes up (i.e. doesn’t seem to be a requirement).

Any thoughts?