Hi Spuluka,
that's quite confussing in these series. We read in a different thread that in fact all the interfaces are only configured under the xe- setion even the box creates as well the ge- section. anyhow we could not find the proper informacion on the juniper documentacion repository. L2 connectivity only started wokring properly when all the access interfaces where configured under the xe- section, even these ones were 1G end nodes ports.
There's no additional SFP added to the box. This one comes with copper bulit-in interafces 3-speed.
Cheers