Wifi keeps dropping, chat assist won't work

Every day, several times a day, my wifi drops. When I use my mobile data to go to the app and use the xfinity chat assistant, all I see is a speech bubble, 💬 like it is typing, but it never answers my prompts or messages. It's infuriating. I don't even have a number to call to speak with human support. Sometimes, my wifi drops, and the light on the modem doesn't even signify that it has dropped. It will be white, but I will still not have wifi. I am so frustrated, can anyone help? My modem is set up correctly, coax cable is tight, its plugged in. I am at a loss.