When I was on the live support chat with Arris customer support, they told me that I should have 3 Upstream bonded channels but it is only showing four. They told me to ask the ISP to reprovision the modem which they did but it is still only showing the three channels
Arris equipment has the ability to bond to that number of channels it does not mean your cable comapny runs that many. TV's for instant can usually tune more channels that a cable comapny carriers too. Welcome to the world of sales, we can use 300 channels but my cable company only has 70? Well if they ever get with the times you'll be ready with this tv thats $300 over your budget but I get more commission for. Salesmen suck everywhere mind you.
There are several possibilities as to why you only have 3 channels,ranging from they don't have the need for a 4th upstream carrier to that space is reserved for the next docsis upgrade [full duplex 3.1 aka 4.0] and so its not available yet for outside testing purposes. It may even be faulty wiring in your residence that you need to pay an electrician to replace, who knows?
If your speed test says BINGO you got it, stop looking into things you would need more information from a private company to figure out. Its like wondering why you are not taking the max dose of a medication, calling the medication maker and having them say ask your doctor to up your prescription. All the while, your tests show you are where you need to be at the current dose. Just a waste of time unless you work for the company.