I am a new user to Antergos and do not have an answer to your question or solution to your issue. I do want to encourage you to be patient, however. I have had a couple of questions and they have both been answered satisfactorily. Modisc may be able to provide clues if you can respond with the response to the command “ip link”.
I think my equipment does a similar thing at times. However, it is difficult to determine if it is the router, my wifi interface or the software/computer itself. I sometimes close and reopen my browser and sometimes reset the wifi interface. I have not determined a reason why I have to do it. To be fair, I have experienced this in other distributions to varying degrees which may mean an equipment issue. Just not sure. Yours is definitely different in that you have the problem with ethernet as well. In my situations, it has been several people who contributed thoughts that allowed me to know what to do. Hope you can get your problem resolved.