Comment 23 for bug 1667750

@l3iggs Nothing is written on it, but it seems to be 470-ABQJ. It came with my Precision.

I thing the culprit is a USB host controller 'ASM1042A USB 3.0 Host Controller' embedded into TB16. See here:
> lshw -short
...
/0/100/1d.6/0 bridge DSL6340 Thunderbolt 3 Bridge [Alpine Ridge 2C 2015]
/0/100/1d.6/0/0 bridge DSL6340 Thunderbolt 3 Bridge [Alpine Ridge 2C 2015]
/0/100/1d.6/0/0/0 generic DSL6340 Thunderbolt 3 NHI [Alpine Ridge 2C 2015]
/0/100/1d.6/0/1 bridge DSL6340 Thunderbolt 3 Bridge [Alpine Ridge 2C 2015]
/0/100/1d.6/0/1/0 bridge DSL6540 Thunderbolt 3 Bridge [Alpine Ridge 4C 2015]
/0/100/1d.6/0/1/0/1 bridge DSL6540 Thunderbolt 3 Bridge [Alpine Ridge 4C 2015]
/0/100/1d.6/0/1/0/4 bridge DSL6540 Thunderbolt 3 Bridge [Alpine Ridge 4C 2015]
/0/100/1d.6/0/1/0/4/0 bridge DSL6540 Thunderbolt 3 Bridge [Alpine Ridge 4C 2015]
/0/100/1d.6/0/1/0/4/0/1 bridge DSL6540 Thunderbolt 3 Bridge [Alpine Ridge 4C 2015]
/0/100/1d.6/0/1/0/4/0/1/0 bus ASM1042A USB 3.0 Host Controller
/0/100/1d.6/0/1/0/4/0/1/0/0 usb3 bus xHCI Host Controller
/0/100/1d.6/0/1/0/4/0/1/0/0/1 bus USB2137B
/0/100/1d.6/0/1/0/4/0/1/0/0/1/5 multimedia USB Audio
/0/100/1d.6/0/1/0/4/0/1/0/1 usb4 bus xHCI Host Controller
/0/100/1d.6/0/1/0/4/0/1/0/1/1 bus USB5537B
/0/100/1d.6/0/1/0/4/0/1/0/1/1/2 generic USB 10/100/1000 LAN <<-- EMBEDDED, NOT WORKING
/0/100/1d.6/0/1/0/4/0/4 bridge DSL6540 Thunderbolt 3 Bridge [Alpine Ridge 4C 2015]
/0/100/1d.6/0/1/0/4/0/4/0 bus DSL6540 USB 3.1 Controller [Alpine Ridge]
/0/100/1d.6/0/1/0/4/0/4/0/0 usb5 bus xHCI Host Controller
/0/100/1d.6/0/1/0/4/0/4/0/1 usb6 bus xHCI Host Controller
/0/100/1d.6/0/1/0/4/0/4/0/1/2 generic USB 10/100/1000 LAN <<-- EXTERNAL, WORKING
...

By the way, Dell listed some special driver for Windows at the TB16 page for this ASM controller.