Hi baker_M
My name is Andre Da Costa; an Independent Consultant, Windows Insider MVP and Windows & Devices for IT MVP. I'm here to help you with your problem.
Press Windows key + X
Click Device Manager
Expand Universal Serial Bus controllers at the bottom
Right click each entry then click uninstall
Exit then restart
Windows 10 will then redetect them.
Try reconnecting the drive to see if its detected.
If that does not work...
Press Windows key + X
Click Device Manager
Expand Disk drives
Right click the external drive
Click uninstall
Exit Device Manager, restart then check if its detected.
If not
Open Devices and Printers, locate Unspecified device then manually reinstall the drive. First uninstall the USB Mass torage device driver.