Verizon Actiontec MI424WR - No communication between wired and wireless network

I have a Verizon-branded Actiontec MI424WR wireless modem/router. Machines coected to the router over WiFi can communicate with each other. Machines coected to the router over Etheet can communicate with each other. However, machines coected to the router via Etheet are unable to communicate with machines coected to the router over WiFi.

How can I configure the MI424WR so that machines coected over WiFi and Etheet can communicate with each other?