I first heard of these guys in uni in Texas. Then when I lived in Albuquerque I knew some relatives of code talkers but never met a code talker in person. I knew a couple of Navajos named Nez. I recall that being a pretty common Navajo surname, lots of Nezes around, but I guess they were related to Chester.
I remember reading that a lot of the Navajos recruited looked a little Japanese, at least in the eyes of the US Marines who would “capture” them as spies. This happened a lot, and after taking their “captives” back to the command center, they learned of their mistake.
On the other end, Joe Kieyoomia was captured by the Japanese and held as a “Japanese traitor” because they thought he was Japanese-American. Although Navajo, he wasn’t trained as a code talker. He eventually convinced his captors that he was Navajo and they tried to make him break the code for them. Because the code was not only in Navajo but also used replacement words (“turtle” for “tank”, etc) he could only pick out a few words and they were all nonsense to him. “They’re talking about eggs” – not realizing that ‘eggs’ were bombs. He was freed after the bombing of Nagasaki.