Do USB-3 hubs need a reboot/reset?

Trendnet USB-3 hub TU3-H4/A, H/W:v1.1R
It worked fine on Win7 for about 3 months, and then suddenly, when we plug it into the laptop, it's an unknown device.
The USB3 port is ok, flash sticks work, little portable external drive works.
Tried it on XP - it responded just like Win7.
In their warranty writeup there's not even a phone number nor a web address for contact.
But as we contemplated going the warranty route, we decided to check the power supply. It's ok, 5v DC.
When the power cord returned to the hub, the hub now works fine. Sort of like a reboot situation.
So what made it fail, what made it work?

I have an 8-yr old usb-2 hub which never did that sort of thing. So I'm worried about the integrity of images and backups going through this hub.