Q: DAX—LASTNONBLANK returns blank for string fairly new to DAX and Power BI. I am having trouble making the LASTNONBLANK function consistent when applied to strings. I have two tables that look like the following:

I am trying to calculate the 'Category' column in Table 2 with the LASTNONBLANK function so that it returns the correct Category from Table 1. Since there are multiple entries for the same SKU, I am trying to use this function to select a single string. And yes, there are situations where the Category may be different for the same SKU, in which case the LASTNONBLANK function selects what I want correctly (i.e. reverse alphabetical).
I am currently using the following function:
Category = CALCULATE(LASTNONBLANK(Table1[Category],0))

This function works, but not for all entries in Table 2. I apply it to the entire column, and about a third of the entries populate correctly. The rest all appear to be blank. I've checked the successful vs unsuccessful entries by SKU in Table 1, and I cannot see a difference.
Any thoughts on the issue?
