Help G-Drive won't allow Mac to Reboot with USB3

I have a G-Drive 4TB with Thunderbolt and USB Connections. The unit only has one thunderbolt input. I needed the thunderbolt connections to run a dual display, I connected the unit to a mac mini running sierra with a USB3 cable.

It all seemed to be working well until I tried rebooting the mac, it would hang whenever I rebooted it. If I turned the machine off, it would start just fine. But if rebooted it, it would hang.

I thought it was something else so went through every device one by one and even reinstalled OS X Sierra from a time capsule backup. then I tried unplugging the G Drive and it rebooted no problem. I had no issues with the G Drive disconnected.

Any ideas on this?

I need the thunderbolt port and was really counting on this unit working as a USB3 drive also.

We’ havent seen issues like that happening over USB 3. It is possible a hardware issue is occuring with the drive or with the computer. You can try a few options on your system to see if it alleviates the issue.

I would recommend: Resetting the SMC

& also: Resetting the NVRAM