TV cannot connect all other devices in house work

I have rebooted both router and tv multiple times I even did factory reboot on tv.  I have disconnected and reconnected wifi connection.  Won’t connect to internet.  The tv even says “problem is with internet provider”. I sat for an hr with Samsung and after it all they said it was with Xfinity.  Using the AI chats gets me nowhere.  I have been working on this for hours over days and nothing yet.