i have a lenovo with a RJ45 Card. it connects normally to my switch the the routeur and finally the freebox
i have added a a zUGREEN usb-c multifunction adapter which replaces the cable of alimentation and provide several connections : carte SD, plots usb-c and a RJ45 connection

when i connect my computer with this rj45 connection i see a new adress eth1 connected with an ip adress. But, my first connection eth0 of my native card is "disconnected".

I success to connect the 2 rj45 but one by one, never at the same time

i tries a lot from the manua but without any sucess.
Who can help me?