Free USB port won't see Virus, but hub with 9 things plugged into it does

I'd like to plug my Snow into a free USB port as recommended in the manual, but the port does not recognize the Snow. Yet when I plug it into a hub with 9 other connections being used, it sees it fine. There's nothing wrong the the free USB port, I can plug in other hardware and use it fine. Any idea what's wrong? TI Snow, Yosemite 10.10.5, Macbook Pro 2014