Just a thought:
It's not Cody or Kote, it's Koté (kōt-æ).
...
No one ever said that the Mando'a to Basic pronunciations/spellings we have are exact, it's not a far fetch if when writing his name Koté, a Mando'a word, in Aurebesh liberties are taken on account of Aurebesh not having accent marks.
As to everyone calling him Cody, most Jedi and everyday citizens wouldn't know Mando'a, it would be like how English speakers used to (and still do to an extent) change names for easier pronunciation. Miguel = Michael, Yeshua = Joshua, Pièrre = Peter. It's not that far of a stretch.
*None of this has any connection to canon like at all.