Value turned null after expanding table into rows

Hi,

I joined two tables that have transaction data and fiscal calendar. All the dates in transaction data has a match in fiscal calendar and after merging, when I clicked on the table, I could see the calendar values. However, after expanding the table, the value in that same row turned into null.

This happened for just a few dates and not all. Have anyone seen this problem?

These tables only have one value since it's just the fiscal calendar date. Is there any other way I can get the values out into column to avoid this error?

This is the screenshot before expanding the columns

before expandingafter expanding