Epson printer can’t connect to Wi-Fi home network and tv in bedroom constantly blacks out

Got a new gateway Xb8 3 days ago now Epson printer won’t work and Sharp television blacks out randomly Tech came out yesterday and got everything working, except printer(my fault because I forgot to check it before he left) however that night tv occasionally blacks out and tv box needs reset.  Xfinity had me upgrade to 3 new TV boxes and a week later offered me this Gateway upgradeTech did a great job, but I am paying too much for Xfinity service to have these recurring problems

I did not have these problems with my customer owned Arris modem.

I need help correcting these issues