F35 Server ARM edition Ethernet port not found

Debian is far behind with kernel versions. So it is possible that an update made changes where Debian is just aware in some weeks or month.

Have a look if you can install the program inxi
Then make us an:
inxi -Fzx in terminal and post the output as </> Preformatted text here.
So we do see what hardware got detected and what driver is used.