These problems started for me in October 2017. I am in Davie, Ft. Lauderdale, FL.
I have had house rewired, DVR replaced, wires to house replaced, filters installed/replaced, all fittings replaced. Techs have said signal is low (sometimes below 30). 800 tech support sometimes sees signal problems and their "system refresh" works for a few days, then problems start again.
JB854393 (maintenance dept - probably the real problem, in system from pole back to Commcast)