Try a couple of things - nothing to lose...
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Do a quick check that all of your coax cable connections are in nice and "finger" tight - at the Hub and wall box and also at any connectors etc. Ensure there are no “unterminated cable loose ends. Disconnect all the connections and reconnect to be sure. Also check that the internal wiring is ok with no kinking or chaffing, check that all looks good with the outside cabling and wall box No nails piercing the cable insulation) .
Then do a Hub “pinhole reset” Disconnect any ethernet cables from the Hub (leave the coax connected), and then with the Hub still "switched on" throughout, press the rear reset pin in firmly to its "stop point" a with paper clip/SIM tray tool or similar "thin thing" and hold it there for at least 60 seconds, release the pin, leave for 10’ to stabilise - dont manually switch it off at any time. See if that improves it
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John
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I do not work for VM. My services: HD TV on VIP (+ Sky Sports & Movies & BT sport), x3 V6 boxes (1 wired 2 WiFi,) SH2 in modem mode with Airport Extreme Router +2 Airport Express's. On VIVID200, Talk Anytime Phone, x2 Mobile SIM only iPhones.