FYI I did a external speed test, and hit pretty good speeds and the link speed never changed… I’ll be able to do more testing once I toss the 10g card in the NAS, hopefully this weekend.
At a guess I think it can’t maintain a 10gig link so it’s throttling down to 5gig as the Nbase-t spec allows, what is the spec and length of cable ?
Check if any power saving features are enabled in the driver properties. Windows might be slowing the 10 gig card when it’s idle and averaging the reported speeds.
When I ran these lines many moons ago I think all they had was that fake spec cat 6e? I’m fine with 5gig but I have a few more things to try before I give up on 10gig. Its about a 45 foot run from my office to the wiring closet.