Setting up the MoCA adapter

I used a 3-way coax splitter to connect the wall, cable modem and moca adapter, then connected the moca adapter and router with Ethernet. Is this setup correct?

I have a total of 4 google mesh pucks in the house. One of the puck is in a room with coax outlet, but the other 2 locations does not have a coax outlet.

As soon as I connected the moca adapter, I lost internet in the entire house. Once I reversed the connection (not using the moca adapter), WiFi is working again.