Smart TV getting bad WiFi connection despite having XFi pods

We have a big house and our WiFi connection was pretty weak. So we opted to buy a three pack of XFi boosters. I put one in the master bedroom, living room and kitchen. The tv in the bedroom is connected to the correct pod and works great. The living room TV on the other hand, is not connected to the pod next to it. Instead it’s going through the gateway and has a horribly spotty connection. It’s a $2k Sony TV so you can imagine our frustrating getting a pixelated connection-
Despite paying the extra $100 for the pod. We thought it was the TV at first so we returned it and got a new one. Nope same problem. Any help appreciated we are at our wits end here!