Trouble Connecting a Multi-Port Switch Directly to Fiber Internet

I just bought a switch because my wi-fi router didn't have enough ports. I connected my fiber modem to the switch. From the switch I have ethernet cables connecting to my wi-fi router and other devices. What's strange is the wi-fi router gets an internet signal and all wi-fi connected devices have a good signal, but none of the devices using an ethernet cable direct from the switch get a signal. Can this fiber modem only generate one IP/signal - and for some reason it's prioritizing the wi-fi router?

Thanks for your expertise!