I've been struggling with this issue for years. My mac (now a brand new iMac 2019 5K i9 model) is getting internet connection issues when I leave WIFI active while it is connected to the wired network ...
If you’ve got working Wi-Fi but your wired ethernet connection is not working, the first thing to do is turn off the Wi-Fi. Believe it or not, this might tell you that the ethernet is working. If ...