I recently purchased a USB 3.0 hub and I am having issues with it power cycling my external hard drive (USB 3.0 only, no power). When the AC power is plugged in to the hub it will turn the hard drive on and off continuously. When power is not plugged in to the hub it seems to work fine for powering the hard drive. This is the second hub from the manufactuer. The external hard drive works fine if plugged directly into the computer.

How do I go about figuring out if this is a Ubuntu setting or something causing the issue?