May I ask a stupid question of the OP, please?
I certainly don't want to teach anyone to suck eggs.
I had this problem years ago, and I changed my cables pinout to a different way and it worked a treat. I am unable to find the original diagram that I used to carry in one of my cases for future reference, but I found a similar one.
We should all know about T568A & T568B types of pinout, here is a simple three option guide, which looks similar to the one that I used to use!
Hope it helps, certainly worth it if you have the kit. https://www.pinterest.co.uk/pin/696017317397807377/
PLEASE don't confuse this with the common phrase of a "Crossover Cable" as T568A & T568B both
have Crossover pinouts!
If you have the kit to do your own wiring of Cat 5e or whatever and some RJ45 males around it may well be worth trying as it definitely worked for me, OR, triggered something in the Drivers or Windows, that made it work much better and faster!
Either, you decide! I still don't know to this day why such a simple change should make such a huge difference, but it did!
I take it you are going straight from one PC/Laptop to another PC/Laptop?
In which case it is the identical problem that I had and this cured it first time!
BT 80/20 and Mobile phone package. Happy with both
"Aquila non capit muscas uel timet latrantem canem"