@Fussil 

Good day.

Thank you very much for your time and patience.

Sorry for the delay.

I used to get the similar feedback before and could not get more details for further analysis.

So could you please help me check the following information：

1. Have you tried with different cables, like cat6, even cat7?
2. How long have you had the adapter and did the issue start out of box?
3. Have you tried to test with a different wired computer and connect to the same port with Ethernet cable directly to check the link speed again;

Thank you very much!