I write software for a living, I know how to troubleshoot stuff. Troubleshooting is all about isolating the variables to narrow down what is broken.
By plugging in via Ethernet it removes wifi from the equation. If the new machine still has problems they know the issue isn't the wifi card and is something else. If it doesn't then they know to look more into what is happening with the wifi card.
Keeping just testing with wifi doesn't tell you anything new.
Edited by andynormancx (Wed 03-Jun-20 21:23:06)