Tables but one of several charts not updating automatically

[sts8500man]

I am new to using tables in Excel. So far, so good, except for one problem that makes no sense to me. I have line charts to represent the data in the table. All of these charts update automatically with the input of new data - except one. The only difference in the charts is that the one which is not updating automatically is one in which the Y axis data is calculated data instead of inputted data. The cells still contain a value calculated by the formula for that cell. A static chart of those values can easily be constructed so I don't understand why it does not automatically update with new "calculated" data. Any ideas or statements about what is wrong with this effort and my understanding of how it works?

sts8500man