Poor Ethernet performance on Dell XPS 13 9360 - normal?

I recently replaced the Killer 1535 WIFI card in the Dell above with an Intel AX210 with no issues. I have 300 MBPS internet service. Now using WIFI, I get around 330 MBPS download speed. I then hooked up an Ethernet cable via a quality USB-C hub, since the XPS does not have a built-in Ethernet port. Through the wired connection, I am getting only 120 MBPS download speed. ????? Is this normal for the XPS 13 9360?

I am running the latest Windows 10 20H2 and as I have the Intel Driver and Support Assistant (which automatically installed the AX210 WIFI/Bluetooth drivers via wired connection), so my drivers are all up to date.

This USB-C hub is a quality unit, as I tested several before settling on this unit:

https://www.amazon.com/gp/product/B073VKGFBM/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

A lot of these USB-C hubs won't run a USB CD-ROM fully when connected to it, due to lack of juice. This one did and had no problem reading and playing back disks.

My Dell XPS 13 9360 was manufactured in 2017 and has Service Tag .