Internet Connection Issue

Hi - My comcast connection has lately not been up to mark. Internet keeps dropping, Poor voice quality over Microsoft team(s) meeting etc.  I've Netgear C6250-100NAS,  performed basic checks such as wires are tightly connected, router restart etc but continue to face problem.  Looking at router event log, I see lot of critical alerts with message "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:0c:6b:6b:77:80;CMTS-MAC=00:01:5c:66:12:5e;CM-QOS=1.1;CM-VER=3.0;"  Spoke to Comcast agent and it was mentioned that they don't see any issue with line and there is no noise interference etc. Any assistance here would be of great help.