My internet & mobile are with Xfinity - cell only has 2-3 bars. But most interested in boosting wifi signal for new Smart TV (my service is through DirecTV) Geek squad tech that installed TV said to check with Xfinity first, then if no help, buy a Mesh Network.
Some tips for improving WiFi performance;
There are other options. Google for WiFi repeaters / range extenders, WiFi mesh systems / pods, powerline ethernet adapters, MoCA adapters.