Dead Ethernet ports on Shield TVs

Has anyone else had a problem with the Ethernet ports on their Shield TVs dying?

I have both the 2015 Shield TV and the 2017 smaller refresh, and the Ethernet ports on both don’t work. (but they used to!)

I am using the 2017 refresh version with a Gigabit USB dongle, but it seems like the native would be better.  I’ve experienced remote control lag since using the USB dongle, and ripped UHD BluRay videos still lag (streamed UHD is usually fine, even via WiFi).

I understand that the dongles basically do everything in software, which can stress the Tegra X1 chip.

Does anyone have any experience with this?  My Google-fu is failing me.  If this is a software fix, or even something I could do with a soldering iron (short of replacing an SoC), I’m all ears.