Brand new XPS 7390.  The right side USB-C port does not work correctly with external USB-C SSD drive.  

When connected, Windows will not mount the drive, and becomes very laggy until the drive is disconnected.  If I connect a standard flash/thumb drive (via a USB-C to -A adapter) it works correctly.  It will not work with other devices, though.

Same devices on either of the left-side USB-C ports work fine.

Is there a defect with the 7390?  I've read of older models having a similar issue with the right-side USB port.  

Advice?