That's pretty odd. Might be a bug, or it might be that someone has manually inserted a second hyphen.
What happens if you increas the width of the frame so the word doesn't need to break there? Do you see one hyphen of two? How about if the frame is the same width and you select the word and change the language?
When i increase the width of the frame, the hyphenation returns correct. When i change the language, the "wrong" hyphen disappears too. The fact is, the whole text i am working in is in Portuguese, and this is happening in multiple compound words. I need to find a way, at least, to detect when a line starts with a hyphen; finding these issues just reading the text is out of question... The text is too large...
This double hyphen that appears sometimes in the text came from a rule called, in Portuguese grammar, "translineação". Is in effect in all the countries that have Portuguese as their official language: http://www.planalto.gov.br/ccivil_03/_Ato2007-2010/2008/Decreto/D6583. htm
North America
Europe, Middle East and Africa
Asia Pacific