You're downstream signal levels look fine but your upstream signal levels are below what's recommended for the modem. See: https://arris.secure.force.com/consumers/articles/General_FAQs/SB6183-Cable-Signal-Levels
If you go straight from the wall to the modem with no splitters it sounds like you'll need a service tech to fix whatever is causing your upstream signal levels to be so low.
wall to modem with less than a 6ft coax. coax pins are in great shape. No splitter.
Everything inside my house is setup to create the absolute minimum connection loss.
