Ethernet Speed Crashes via DynadockU3

[Oakland]

Hi All

New to the forum so don't beat up if in the wrong place!

I have a Toshiba laptop and a Toshiba Dynadock U3 with Display Link.

If I connect the Ethernet cable to the PC direct then I get normal internet speed for my area as repeat tested via Ookla's speedtest via a browser.

However, when I hook up the Dynadock the internet speed crashes through the floor and sometimes comes to a halt. manifestations include stuttered internet radio, very slow web browsing etc.

Unfortunately, we are in a rural area so crashing through the floor reduces form a typical 6-7Mb to next to nothing!

I have de-installed the Display Link software, downloaded the latest and re-installed.

The interesting thing is that I can attach the Ethernet cable to directly to the PC and just use the Dynadock as the display pass through and the impact is exactly the same.

Has anyone experienced this before and if so is there a fix or any tips?

Cheers

John