Calculated table - rows not showing

Thanks for all the replies.

I have solved the problem this time, but still don't completely understand it:

v-ljerr-msft, I checked the DISTINCT function with the other columns in the same table and found that it worked with all the columns that did not have blank or null values. For the columns that did have blank or null values (including the RegionName column), it displayed the table without showing the rows, but showed the number of rows at the bottom.

Solution: I filtered out the blank values in the RegionName column and it worked fine after that.