U2422HE, Ethernet connection dropping, #2

Getting right to it. 

The Ethernet port on the U2422HE constantly turns off and on, most times faster than I can try to disable it or even remove drivers. 

I have used the default driver, I have tried Dell's suggested "new" drivers, I have tried Realtek's "actual" newest driver, all with the same results. 

I have the HE connected via USB-C to brand new Latitude 7420s laptops with a U2422H (non-hub) on the daisy with DP. 

Most other threads (including the ole Reddit) suggest disabling all power saving features: with either new driver, these are disabled by default. They also suggest updating firmware. The shipped firmware is newer than what is available from Dell. 

Does Dell have this dialed in as an issue? Does anyone have a work around or fix that stops it from happening at all with this actual model? Does anyone know if this is something linked to using the USB-C AND daisy chaining another display? Is it a power issue? Is there a setting I can change with on the monitor itself? Should I try powering the laptop with its AC adapter as well as using the 90W passthrough?

We just purchased 70 of these displays to replace an entire office's worth of displays and bypass needing docks and this isn't a good start to the deployment. 

Thank you.