DAX Formula Help

You could try to aggregate by MIN or AVERGE instead of SUM. However, since it looks like most rows except the Tags are the same, I would try and fix the structure of your data - the first table would be something like the Work Item Table, which would have the Work Item Id, dates, and Story Points, etc without duplicates. And then you might have a Work Item Tag table (which just has a work Item ID and Tags), which would have a M:1 relationship with the Work Item Table. That way, you won't have to deal with the multiple story points per work item.