Hello!
Thank you all for following up.
I made it work using a not very subtle approach: Hard reset both the Spectrum Modem (5 second push of reset button) and Turris Omnia (3 LED reset).
After a couple of attempts everything is working normally.
For reference I’m leaving the details here.
The connections are : Spectrum Modem 2.5G Ethernet Connector marked as Internet → Turris Omnia 2020 WAN port ← Macbook using an Ethernet cable and USB-C network adapter.
The Spectrum Modem was activated successfuly.
The symptoms were:
- The physical link was established (led light up); but the WAN connection would just simply not obtain an IP Address from Spectrums DHCP.