You may find that you have more than one measure in your Flow instance that is measuring the same value! The optimal solution to this is to delete any duplicate measures, so that you are left with just one measure for that particular value.
The problem though is that the different measures in your duplicate measure set may be configured across different charts, calculations, etc., and it is time consuming to find all the references to the measures you wish to delete and change them to the measure that you wish to keep.
There is a feature that allows you to leave that time consuming task to Flow.
There is a caveat though: the single measure that you wish to keep must be a template-linked measure. The reason for this is because this functionality was designed to mitigate the potential duplication of measures when templates are introduced to your Flow instance after you have already configured measures that perform the same function as a newly instantiated template-linked measure.
Then, for each duplicate measure that you find, you need to drag the duplicate measure while holding down SHIFT, and drop it onto the master measure.