The system is mispronouncing the NATO letter “Echo”.
It is currently reading it with a literal Spanish “CH” sound (/tʃ/, like in “chocolate”) instead of the correct international “K” sound (/k/).
It should sound like “Eko”, not “E-cho”.
While it might seem like a minor detail, hearing this basic aviation term mispronounced constantly completely ruins the realism and immersion for Spanish-speaking players.