USB3-HUB7-81X Seven port is 3.0 hub issues

Hello I recently bought two of these in amazon everything was working
perfect but since Sunday afternoon I have problem with my Toshiba usb 3.0
external drive. It disconnects and reconnects when copying large files
500MB or more, therefore not being able to copy.
At first I thought it was my hard drive but after extensive troubleshooting
with both of your units and the Toshiba external hard drive I came to the
conclusion that is your items in the basis I power cycle and reinstalled
drives and update firmware in both units I tried the same setup in other
computer and the same problems appear. But if I connect the hard drive
directly to the usb 3.0 of the mobo the hard drive works perfect I tried to
recreate the issue with no luck. As soon as I plug the pluggable unit and
plug the hard drive to the hub on the first try either writing or reading
etc it fails and hard drive disconnects. I need a solution please.
Thank you,

Felipe serna.