Until an update in the last few days I had single finger gestures that triggered when a touchbar group was opened, and when the gestures was done they closed the group. Basically I was able to reproduce Apple's volume and brightness sliders (without the visual slider on the touchbar). If I dragged from the volume or brightness icon on my touchbar, the TB group would open and the hud would come up on the screen, and when I stopped dragging my touchbar would come back.
After a recent update, the gesture no longer triggers when the TB group opens. I have to tap a second time and drag from there. This no longer works in the current version or the alpha. It does work in 1612. I didn't try any in between.
Very weird, maybe it depends on the Touch Bar model.
To rule out any setting that would interfere with this, could you go to Help => Export Diagnostic Debug Info and send it to firstname.lastname@example.org referencing this thread?