First do a quick check that all of your coax cable's connections are in nice and "finger" tight at the Hub and wall box and at any splitters/attenuators/etc with no “unterminated loose ends – disconnect then 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.
Then do a Hub “pinhole reset” - with the Hub "switched on" throughout, press pin in firmly and hold it there for 60 seconds – release the pin then leave it 10’ to stabilise. But, make sure the 2 passwords on the Hub sticker are still there and legible first !
If that’s all good.... Post up your Hub/network connection details and someone will check to see if there is a problem there. In your browser’s URL box type in http://192.168.0.1 (or http://192.168.100.1 - if in modem mode) and hit return. On the first page up [there should be no need to login if you have done so before] click on the “router status” icon/text at bottom-middle of first page up and then copy/paste 3 FULL sets of data onto here – from the Downstream, Upstream, & Network Logs pages. Don't worry too much about the formatting it can be easily read & DON’T include personal data or MAC addresses - blank them out - if you copy/paste the data, the board software will do this for you (you may need to click the "submit" button a second time).
Also, in the meantime. Set up a free “Broadband Quality Monitor” to continually monitor the state of your connection and record any true network dropouts - it will thus allow you to differentiate between those and simple wifi dropouts. It does it 24/7/365 and it keeps a visual record of any/all of your network disconnections, useful data to have to match to the Network logs (in your Hub settings) and also in discussions with VM - note it will take a few hours to start seeing a sensible picture.