New service installed today, already cutting out

Hi, my house just had Xfinity Gigabit installed today and everything worked fine until a few hours after the tech who installed it left. Since then the internet and TV have been having connection issues every few minutes and whenever it happens the lone light on the provided Arris gateway glows solid red. I already checked the signal strengths as per the comcast_xfinity subreddit and everything seems within the parameters on other threads although I don't have an easy way to screenshot it. Is it just a problem connecting on comcast's end or an outage or a problem with the outside cable? Please help.