Frequent drops -- 20 T3 T4 timeouts in last 6 hr

Had service installed about two months ago, lost service three weeks ago, tech replaced cable from house to box at end of lot. I'm now getting frequent internet service drops throughout the day ranging from a couple minutes to many hours. See pic of Pingplotter graph. Multiple calls to service has resulted in modem resets and no improvement. "Outside" service tech said "all is good outside" today. I've gotten 20 T3/T4 timeouts in last 6 hours. Any help would be appreciated!

https://imgur.com/dXwj6PS -- Modem log

https://imgur.com/2P75tfW  -- PingPlotter graph