GS324 not letting traffic through

Hi there - I upgraded my home network and am having issues.  I have cat6 through the walls to many rooms, connecting desktop PCs and an Xbox One.

my topology is Comcast coax for internet into a Netgear C6300 cable modem + wifi router, into the Netgear GS324 switch and through to ports to different rooms.

Internet access through Wifi (only uses the C6300) works well.  If I turn off Wifi on a laptop and connect it to an ethernet port on the C6300, I also get internet fine.

When I connect the C6300 to the GS324 switch via an ethernet cable, and plug that same laptop via ethernet cable to the GS324 switch, I can no longer see ethernet.

I don't know what troubleshooting steps to take to get the GS324 switch working, and would appreciate help.

thanks

Dave