SSRS tablix Sorting not working on Date column

Question

I have a SSRS report one

Stock#_______Description_____Colum1_____Colum2_____Colum3 ABC__________XYZ_____________4334________4354_______454

detail part 

Transaction#_______Date
1__________________yyyy/MM/dd } Need to be sorted
2__________________yyyy/MM/dd } this date column
3__________________yyyy/MM/dd } but always comes unsorted
4__________________yyyy/MM/dd } Note: (This is tablix)

So one line for master and in detail part showing 4 last recent records. And this is not sub-report. I am getting 4 rows, then grouping by stock# and used tablix to display 4 transactions sorted by recent date (desc). Did every effort but its not showing date in any order. Checked the dataset value, its completely in desc order by date, but reports is not arranging it somehow. Sending date as date, displaying it using Format("yyyy/MM/dd") SSRS function. Sorting using simple date value from dataset. What else I should do here?

Answer 1

After trying many things I found one solution which worked for this problem.

1. Click on Tablix, then row with many eclipses
2. It will show if there are groups on that tablix, look bottom of screen it will show the row groups and columns groups.
3. In Row groups, you will see many columns, right click on first column in Row groups section.
4. Select Group properties..., then on dialog, select sorting, by default it will be showing the first column name, change to the desired column and sorting order by [A-Z] or [Z-A] button.

This worked exactly what I was looking for. This link helped me https://msdn.microsoft.com/en-us/library/dd255193.aspx