I realize this is kinda dabbling into the techno-nerdish wading pool, but lets give it a quick look-see: I've had no answer from the site guru, but I've concluded that the plain text input software for story submissions that is also used to translate the "filename.md.txt" files coded with "markdown" punctuation that I love to use for auto-HTML generation ... well, I'm guessing that the site's "filename.txt" or "filename.md.txt" input translater doesn't honor the UTF-8 character set. (I'm thinking that it is stuck back at ANSI)
Today I used my "chapter_21.md.txt" file to generate an HTML version, "chapter_21.html", made sure the header specified the UTF-8 character set, and uploaded that to replace the original posting.
Problem solved. the word now displays as "perdóname" as it should. So, it's more work for me to generate the HTML file, but not much; and you get to avoid wondering what those garbage characters are.
(end of techno-nerdish boring stuff)