As I understand your situation, and I may be wrong, you have an existing freeview set top recorder which connected to your old TV with either a scart lead or HDMI cable. This set top box required an antenna to be connected to it. Nothing has changed just because you have a new TV with built in Freeview. They are two separate unconnected signal paths. Have you simply used the existing antenna cable to connect to your new TV, in which case the set top box has no signal input to enable it to work.
Google Home Hub review