thousands of uncorrectables on CM1200 modem

recently started noticing lag spikes, bad ping, unstable connection, etc. I logged into my modem (192.168.100.1), and noticed thousands of uncorrectable errors.

picture here: https://i.gyazo.com/7c38a9ca71cc046e12906f28f16a4f68.png 

i did recently switch to gigabit ethernet with comcast. i had to upgrade my modem, which is why I got the CM1200, since my older modem couldn't handle those speeds. A tech did come a few days before I switch to gigabit, and he swapped some fittings on the wall and outside. so it's possible he made it worse.