DELL Latitude 7275 - External Storage / USB / SATA

Hi Guys,

My notebook keeps disconnecting my USB docked SATA drives.

Hardware;
- DELL Latitude 7275 Tablet Notebook
- VL-DS30 Dual SATA USB Dock
- WD 3TB SATA
- WD 2TB SATA
- SG 500GB SATA

I also have two other unknown single SATA docks.

The device recognizes and loads the drives, then drops them within 30 seconds.
After physically disconnecting the USB cable, I am able to to re-establish connection.
The process repeats.

The drives have stayed connected for long periods, +12 hours.
At some stage overnight I'm guessing they go to sleep.
Upon re-connection, the issue occurs again.

I cannot identify why the drives stay connected when they do.

Troubleshooting ;
- checked windows power management / NO HDD SLEEP OPTION.
- checked bios power management / NO HDD SLEEP OPTION.
- checked device management / USB > PWR MGT > ALLOW PC TO PWR OFF - UNCHECKED.
- replace power outlet / NO RESULT.
- replace power cable / NO RESULT.
- replace USB cable / NO RESULT.
- replace USB SATA dock / NO RESULT.
- replace SATA HDD / NO RESULT.
- supportassist update BIOS / NO RESULT.
- supportassist update all drivers / NO RESULT.
- supportassist optimization / NO RESULT.

TL;DR

The issue only occurs on my Dell Latitude 7275 Notebook.
The issue occurs on all docks, single and dual.
The issue occurs across all drives.
The issue occurs across all cabling.

The only constant is the Notebook.

I've seen some threads about gfx drivers on other dell machines causing similar issues.
But they were on other hardware, other drivers.
I don't want to start rolling things back randomly.

Any help would be appreciated.