The thing is, lots of us didn't order on Thursday and we still got a code anyway. I waited until a full 24 hours had passed.

Friends who ordered on the website got their codes, so there goes the theory that only the phone app worked.

About the only thing I can think of at this point is that there was a window during which they incorrectly disabled the code on Thursday, but then re-enabled it on Friday, and if you ordered during that window of time, you didn't get credit for it.