The counter on the unlabeled frames gets messed up when you type the label names quickly. This behavior also shows up sometimes when allowing the OpenCV to do the labeling. Going in and out of the video will fix the counts, so it is not a big issue, but just a small bug.
Attached is a screenshot for a scenario where on the first frame we just kept changing the label name by typing the name and deleting it repeatedly resulting in a negative count for unlabeled frames.
