valis2k Welcome to the community!
The installation has just been completed in the system. Please disconnect your modem from power for about 10 minutes and then turn it on. Wait about 10 minutes and then connect a computer via LAN port and test it again.
If it does not work, connect the antenna cable directly from the cable outlet to a TV and perform a channel scan. If no channels are found, your connection may be sealed.
Greetings
Daniele