Hi @Franules, try plugging the disc you're trying to factory reset into your router with an ethernet cable, then press the pinhole to reset it.
Make sure you keep the main disc plugged in when you do this (so that you disc gets its settings from the main one).
Hope this helps.
Hi again, someone else here had the same problem and got a solution, which someone successfully used again yesterday. Does that help?
If that doesn't work, contact the helpdesk using the details on that other thread.