As you can better see on the screenshot below, the predicted count of unlocked concepts and exercises after marking an exercise as complete does not correspond to the actual count.
Plus, the number of 78 exercises seems way off. 
Some more context to track the issue:
The exercise is Currency Exchange in Python.
I completed the 12in23 exercises in practice mode before coming back to learning mode.
I also had other concepts, further in the track, already completed (Condditionals, Strings and Comparisons). Here is a screenshot of my track state:
