Java constant String gets corrupted in Android

I'm collecting data from users' devices for analytics. I've got some final static Strings representing event names (e.g. "banner_click"). As the appropriate event occurs the event name gets stored in sqlite database, after which I periodically read them from DB into JsonObject and make HTTP request to send the collected data to our server, but sometimes we get corrupted event names the server ("banner_clıck" instead of "banner_click", "i" is replaced with "ı" in all such cases). This case happens rarely, but it worries me. So I'd like to know how come constant string be corrupted, I cannot reproduce it myself. My only guess for now is that it's a device specific issue.