Correlation Between Threshold Values

I recently did a breakthrough workout whereby my threshold increased from 197 to 213 and my signature was updated accordingly. When I look at this workout by hovering over it in the progression graph, it shows 207. However, if I look at the advanced tab it shows 217. I wanted to understand the correlation between the two numbers as I would have expected the value in the progression graph to be 217? Thanks

The progression chart shows a 42-day moving average value, in line with the exponentially weighted values. Individual activities may be above or below that line. We are considering an update to show individual values rather that averages.

Thanks for the clarification