This is not something you can fix with new phones alone if the line isn’t generating a ring signal.
If your phone is plugged into a wall socket the most likely cause is that the ring generator on the exchange line card failed while dial tone and audio still work. This fix can only be done remotely, so a tech visit won't help.
If your phone is plugged into the hub's TEL 1 port the most likely cause is the ATA (analogue telephone adapter) subsystem behind the TEL 1 port is not generating the ringing voltage. A hub swap will resolve this but go along with a reboot first if told to do so (it probably won't work but go along with the process).