I am certain there is something wrong here, and it is not just a question of timing. Yes, timing is why the bari notes aren’t playing in some cases, but that is because Dorico is evidently calculating the time wrong sometimes. Please consider the two examples below. Example one has the note starting the gliss as a half note beginning at the bar line. The gliss is “delayed start”, so the time available for playing the gliss notes is half of the note, or the space of a quarter note. That plays perfectly at my song’s tempo.
Now look at example 2. Everything is exactly the same except that the note beginning the gliss jumps 1. In other words, the beginning note is LONGER than in example 1. It is something longer than 2 beats. We do have swing set, so it is not a full 2-1/2 beats, but it is LONGER than example 1. And of course, half of a longer note gives us more than a full beat to play those gliss notes. But the gliss fails to play in this case.
To try to work around this, I tried several settings for delay. None of them sound nearly as good as example 1, but I got something to sound more or less like real notes by setting the delay down to 5/8 of a beat. Anything larger and it is just faint clicks. Again, I’d expect a delay of 1 to produce a result very much like Example 1, but that doesn’t work.
I thought maybe the fact the note was starting before the beat triggered the problem. Consider example 3. This is exactly like the other 2 examples with delayed start on but no delay specified. This time the note beginning the gliss starts on the beat but is 2-1/2 beats, like example 2. This time the notes definitely sound – but now they are compressed into a half beat, when they should be in the space of something slightly over a full beat.