Hi blob. I’m not familiar with your hardware, but let me give you some of the hangups I’ve had on Debian installations on PC.
you should comment out your wifi & ethernet interfaces in /etc/network/interfaces so Freedombox NetworkManager may control these. ( Net install, then apt-get install -y freedombox, then comment the interfaces out, then reboot and configure freedombox )
when you have multiple interfaces Freedombox wants to use the first interface detected by the kernel as the primary interface ( to internet ). This is not the same as the first interface in name order. My eth1 is picked up first by the kernel first, not eth0. I’ve had a PCI ethernet card be primary before the onboard ethernet.
Make sure you do not configure Bind if you are using Freedombox as your router ( internal network connection is type “Shared” )
also, check for duplicate IP just happened to me tonight when I was trying to set up a new installation.