Very bad bitmain !!! I have successfully add 2 unit to my kart but after 30 minute of refresh and reload the web page i receive the Message of out of stock !!!! Wake up in the night and then This !!! Very very bad !!!
yeah, that is normal under heavy load server.
try again next time
in the spirit of waking up, at least buy couple of power supply. u can even resell it if you feel stupid to hold it.