MOCA works on coax outlet, but not Xfinity Gateway.

I currently have my Xfinity Gateway (XB8) on the 1st floor of my house.  I also have a separate router on the 3rd floor, hooked up to the internet via a MOCA adapter.  I used to have the XB8 Gateway connected directly to the cable for internet service and MOCA setup with the existing coax of my house, but recently I tried using the MOCA built into the XB8.  It works fine, though the actual speed is slower than the other setup was, since the XB8 is only MOCA 2 and not 2.5 like my MOCA adapters.  Setup is service cable for internet going to a POE filter, then to the input of a MOCA splitter.  The 2 outputs go to the coax wall outlet on my 1st floor near the XB8 and the coax wall outlet on 3rd floor near router.

The router is showing it's age and drops the internet connection, wired and wifi, when my kids are gaming online.  I assumed that I would be able to just flip flop the router and the XB8 Gateway.  However, when I connect the Gateway to the 3rd floor coax outlet, it never connects to Xfinity, I just get the blinking orange light.  I tried doing a reset, nothing.  I tried doing a factory reset, nothing.  I disconnected the service line from the POE filter and MOCA splitter and did a direct connection to the coax cable that feeds to the 3rd floor, did another factory reset.  Still nothing.  I know the cable is connected because I can have 2 MOCA adapaters recognize each other (the moca light is lit).  Can a splitter that might be in the walls affect the Gateway from receiving a signal from Xfinity, but not have an effect on MOCA?