Most likely there is a bit or dirt or other matter that got between the rim
and the bead. I would guess that the area would need to be cleaned and
the tire would need to be re-seated at minimum. Could also be a bum
tire, but would hope for debris
As stupid as this sounds, get a mallet and hit the tire where it's leaking a few times. You can try hitting the tire on the crown and/or the sidewall. You should be fine. Remember to always check the balance yourself as the tire guys tend to do the minimum.