Only one upstream channel locked

Start with removing any amplifiers, signal attenuators, or splitters from the coax.
From there check the line for kinks, damage, moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.
If you can, simply connect the modem right where the coax comes into the home. This prevents wiring in the home from being the issue. And some ISP’s charge if the wiring issue is in the home. So this helps prevent this.

You upstream/downstream values aren't where'd I'd expect them if you had a clean line. Reason why is you're on the higher end of the downstream values. Meaning you are either close to the hub or are using an amplifier. But your upstream values are indicating its needing a bit of power to communicate back to the cmts. So its either further away or something in the line is causing signal attenauation.