I have been having poor internet quality for a few months now. In the past I've been able to correct the issue by removing the coax able from the modem, waiting for the modem to flash, then turning it off and reconnecting the cable and turning it back on. However in the last few weeks it's been getting worse and worse and no amount of restarting the modem seems to help.
I have not had a Comcast tech on-site yet. I've chatted with Comcast support a few times and they've reset the modem but it hasn't helped.
I have a router, but all of the information below is from my computer being connected directly to the modem.
Modem Make/Model: ARRIS SB6190
Plan Speed: 150 Mbps
Upstream and downstream signal levels: