I thought there was a bug with UTF-8 plain-text files, but there wasn't one. I still want to share what happened here in case someone else runs into the same problem.
I downloaded a plain-text .txt file from gutenberg.org, which was in Spanish and encoded in UTF-8. The source of my problem was that I saved it from within the browser tab, as Firefox loaded the text file instead of prompting to download it.
The file was saved as UTF-8 but unsigned. The eReader will not recognize special characters unless the file is using signed UTF-8 for character encoding. I have verified this by testing different text files.
I went back to gutenberg.org and right-clicked the link to the text file, and chose "Save link as..." which downloaded a signed UTF-8 plain-text file. It worked perfectly in my eReader!
I downloaded a plain-text .txt file from gutenberg.org, which was in Spanish and encoded in UTF-8. The source of my problem was that I saved it from within the browser tab, as Firefox loaded the text file instead of prompting to download it.
The file was saved as UTF-8 but unsigned. The eReader will not recognize special characters unless the file is using signed UTF-8 for character encoding. I have verified this by testing different text files.
I went back to gutenberg.org and right-clicked the link to the text file, and chose "Save link as..." which downloaded a signed UTF-8 plain-text file. It worked perfectly in my eReader!