Regarding Observation 478204 … Are the three long dashes between groups of Morse Code characters meant to be part of the Morse Code, or signaling/timing tones? They are not Morse Code characters sent at the same WPM as the data stream. Unless the decoder recognizes these tones as ‘trash’. most of the decode will fail and/or have erroneous characters.
If the dash duration is significantly longer than the proper dash, the decoder drops that symbol.