USB ports not working.

[pmtremblay]

Thumb drive devices (2.0) are working properly in any of the XPS USB ports.
HD devices (3.1) are not working properly (drive is spinning, led is flashing but no access to the data) when connected to any of the Dell XPS USB ports.
These HD devices (3.1) work when connected via a USB-C to USB 3.1 adapter. The one I use is CharJenPro USB-C 3.1 HUB/Adapter.

Is this normal behaviour or should all the XPS USB ports be working properly with USB 3.1 devices?

Thanks.