Confused about synfire detection

Just a guess, but could it be because of the playing range of whatever instrument you're using?

As well as the playing range, it could also be that Synfire has made the highest note the Anchor.  You can override this in the take manually, by grouping the notes together and making the lowesst note the anchor before appying the recognition.  What happens if you do that?

Another possibility.

I use both Reaper and Studio One DAWs.

I was doing some note based articulations and they weren't working in Reaper.

It turned out that Reaper's midi note names were an octave lower than the same note names in Studio One.

In other words, could your DAW use a different octave for the notes than Synfire does?

To test, export your midi and open it in another DAW (or two) and see what happens.

Or listen to see if the same notes in Synfire are actually an octave higher.

I actually meant change the anchor in the Take, you're changing it in the Figure.  Try selecting the Take in the phrase editor, changing it as I said above, then doing another figure recognition.

If that's the case, the simplest thing might be to lower by one octave, anything that's going into Synfire.

Unfortunately, there is a lot of variation between programs as to the correct octave for a given note number, but once you know what they are, you can compensate, at least.

Strange how it still sets the highest note as the anchor after recognition.  I originally meant to group the notes first in the Take (you can do that as well) and then make the lowest note the anchor.  Would be interesting to know what happens if you do that.

There is this quote about it in the manual:

Human eyes are still superior to technology. If you already have a specific idea as to which segments the figure should contain, you can already start to group and select the symbol type in Take, exactly as you would with a figure (see "Phrase Editor"). The figure recognition will gratefully accept your assistance and deliver appropriate results.

Now the middle note has the blue triangle over its head after recognition.

The anchor key is the square grey,then now we have two anchor keys,the lowest and the middle notes.

If I see things correctly in your video, you have not grouped the three notes to a figure-segment, but only the first and the last note are grouped. The middle note remains isolated. Therefore you have actually two figure segments and therefore two anchors. 

I don,t know what means the blue triangle?

It means that this figure-segment (in this case only the middle note) is assigned to the upper playing range of the instrument. You can change the assigned playing range with the playing range buttons at the tool bar.