[SOLVED] Paying for 300 Mbps, Getting 50 on PC (Other devices getting what I am paying for)

Solution
So you had this issue on the old motherboard also ?

Did the old motherboard run the same chipset. Many motherboards using the z590 have 2.5g ethernet ports. There have been all kinds of driver issues, it was so bad that some boards made about a year ago had a design flaw in the 2.5g intel chips that could not be fully fixed with drivers. Even now you still see people having strange issues with these ethernet chips. Generally the best driver to use is directly from intel but there are conflicting reports which exact dated driver you should use. I would try the newest and if it makes no difference try a older one.

If you get this to work make sure you disable windows ability to update drivers. Windows has been known to...
So you had this issue on the old motherboard also ?

Did the old motherboard run the same chipset. Many motherboards using the z590 have 2.5g ethernet ports. There have been all kinds of driver issues, it was so bad that some boards made about a year ago had a design flaw in the 2.5g intel chips that could not be fully fixed with drivers. Even now you still see people having strange issues with these ethernet chips. Generally the best driver to use is directly from intel but there are conflicting reports which exact dated driver you should use. I would try the newest and if it makes no difference try a older one.

If you get this to work make sure you disable windows ability to update drivers. Windows has been known to load old drivers or generic drivers when it does updates.

What you might also try is to boot a linux usb image. Most these images have support for this intel chip and it would show if it was a hardware issue of some kind.
 
Solution