Internet out

Issue started March 1st. Had a tech out on Sunday 2nd, he found no issues, (because of course everything was running fine at the time) he stated signal level was good: Everything worked fine all week until yesterday 3/9 around 8pm, same issue signal craps out, ping test reveals up to 81% packet loss until modem light goes red and stays there for 2-3 hours then comes back and is mostly fine. Today 3/10 it runs well all day until around 8pm signal dumps, ping test 75% loss until red light. I've reset the modem during these times.