Client PPPOE not connected TIM ISP ITA

Hi,
I ve configured my rb2011 uias Rm as router and I ve connected on eth10 as wan . Also I ve applied nat masquerade on eth10 and all ports are on line. Obviously eth10 is out fron bridge.
If I try to configure a pppoe client on eth10 as out interface, pppoe client is disconnected or try to connecting but not successfully!!! ISP is Tim fiber connection (Italy) and I ve asked to isp my password and user! Sometimes client answers in red “ client is on slave port!”
Could you help me?