New house ceiling lights work but not pendant lights
On homes where we wired the home with extra locations like your pendant lights but did not install them we did not wire the connection at the switch either.
It would not take any longer but some inspectors will flag unused hot conductors.
Or to say it differently the hot wire to that string was not connected for safety reasons.
We usually did connect the neutral and ground and would wire nut the black.
In the switch box look for a disconnected wire, that can be landed on the switched side of the switch (not always hot side) or a double switch can be added.