Hello  @sadcenter 

 If trying to change Network adapter Speed to Auto Negotiation , what is the wired link speed on adapter

1. Please confirm the router port is 1000Mbps port or it's a Gigabit router or Ethernet adapter can not negotiate with it at 100Mbps. 

You might check with router support and see if there is setting on router to change the port speed, force the port speed to 1000Mbps.

2. Disable other network adapters except the tp-link wired adapter 

3. Try a different Ethernet cable 

If the same, can I have know the model of router that the PC( adapter) connected to, do you have any port speed settings on the router? 

 Hello  @sadcenter 

Thank you for more test and sharing more information here.

If you have a different Ethernet cable, test a different Ethernet cable 

To better assist with your case, I created a support email  TKID220704347 to follow up further, please check your email inbox for a new driver.

 Glad to know you have sorted out it was the bad Ethernet cable. Thank you for updating solution with us in the support email.