Little to no internet using 10GB ethernet port on Bootcamp

When using bootcamp, I have little to no internet access on my 10GB ethernet port. I have 1GB up/down fiber ISP and I get almost full speed on the iMac and a 11 yr old Windows 10 PC.

I did a fresh bootcamp install of Windows 10, completed two Apple bootcamp updates, then did the Windows 10 updates and still the same problem.

If I disconnect the wifi, same problem. If I disconnect the 10GB ethernet cable, then I get normal internet, but only about 25% of the capacity (app 250MB up/down).

Any ideas?

TIA