Something is wrong in the automatic text correction. I programed it to subtitute "---" by the big line that appears when you press "alt+0151" and after I closed the page and open it again to write some more I noticed, when zooming, that what had appeared on the text was not that big line but the medium line ("alt+0150") followed by a small line ("-"). I had to replace the big line manually.
Hi jlbraga, thanks for reporting. I think not such bug, what happens is the replace for '--' is applied. Perhaps the only option is delete the '--' autoreplace. Please if you are not agree, reopen it.