Yesterday, my iPhone home button stopped working, restarting and synchronizing the device didn’t help – so it didn’t seem to be a software issue. I could further prove that by testing out the button very strongly, and in fact I found a spot in the upper left side of the button where a strong press could activate the button.
As I had this effect once before and it went away magically all by itself, I thought of just waiting a bit. One hour later when I was at work, everything worked normal again. Maybe it has some connection to heat, humidity of the air, particles between moving parts that had released themselves on the ride by bike that I do when I go to work. So, if you’re having this problem, my advice is waiting a bit, and retrying over a full day till sending it back.