Just bought ER-4 about 2 weeks and issues found, been up and running since it was delivered.
I just looked at the history of my order and it sold by Amazon if that matters.
Sold by: Amazon.com Services LLC
Now the one thing I noticed was that I had different box than the one from this youtube video.
https://www.youtube.com/watch?v=EMu8Pi73ses&t=605s
My edgerouter came in a brown Ubiquiti box.