Fill blanks with previous values

J94 Well, yeah, because in your data you don't have any previous sales for the products that are blank. You are basically running into an Auto Exist issue. Essentially you are attempting to invent data that doesn't exist. The measure is not going to calculate on rows it feels are invalid. They were supposed to have fixed the auto exist issue with allowing you to select "Independent" as the "Value filter behavior" for the semantic model but it doesn't work in all cases, like this one. Essentially, Power BI isn't even attempting to calculate the measure.

You could add a column and that should work but, again, you don't have any previous week sales in your data for the products that have blanks. So...