Gram 17" - ethernet to USB C adapter kills a slow internet connection

First post here - hi

LG Gram 17 2020 - love it, but going on from http://forum.notebookreview.com/threads/slow-speeds-with-usb-c-to-ethernet-adapter.830302/ , I have a problem at the other end of the scale, with v slow internet connection already, the Gram slowing it down even more.

Our other computers get 1.7Mbps whether by wifi or by cable direct to ethernet port, which is just about adequate even with Zoom and Netfix with minimal stuttering.

The first Gram we tried got 0.7Mbps using the ethernet to USB C adapter provided, which rose to 1.0 after Network Reset. It got the full 1.7 via wifi.

Sent it back and got a replacement Gram but that only gets 0.5Mbps using the ethernet to USB C adapter provided.

Maybe the LG provided adapter isn't the greatest, 'only' 100Mbps, but higher quality adapters seem to be about even higher speeds, which ain't the problem here.

Any ideas?

 

Would https://www.amazon.co.uk/dp/B07BJJX...ldnntw6ltdn5wq&linkCode=gs2&tag=androcentr-21 be more direct, a different or better approach?

 

USB C to Ethernet adapter costs $5 on Aliexpress and a Thunderbolt 3 dock goes for about $30. So buy it directly from the source instead of paying huge margins to middlemen sellers on Amazon.