I experienced the same issue while tracking my gold SQL Server tag. I needed to reselect the badge from the tracker for it to actually update the graph.
This has been asked-and-answered at "Next tag badge" panel score and answers counter discrepancy"Next tag badge" panel score and answers counter discrepancy - unfortunately, the answer is the workaround I talked about above.
I suppose since this was marked as a bug, it might get some attention in 6-8 weeks.