AutoSort issue when sorting Pivot Table after secondary column

Hai!

Here's my situation. I have a pivot table with a few thousand 3-levels rows and at least one number-based value columns. The table is sorted descending by one of these columns, which has values of 1, 2 or 3 (but there are hundreds of primary rows, which are distributed among these three values).

The sorting is fine, however when I try to expand a primary row, the ordering of the rows changes. It still remains descended by that column, but the ordering of the rows with the same values is different. When I collapse the row back, the ordering reverts back to the original. This issue doesn't appear if I try to sort by a different column, and seems to be fixed if I disable "AutoSort" (which I don't understand why).

To give you an example, let's say this is how it looks when it's collapsed:

+row1	3
+row2	3
+row3	3
+row4	2
+row5	2

This is how it looks after I expand the first row:

+row2	3
+row3	3
-row1 | ---subrow	3
+row4	2
+row5	2

The order changes (though it's still ordered descending by that column).

Any idea why this might happen?

Thanks!

So, no ideas on what might cause this?

I could just disable autosort, but I'd rather find out what's going on.

Cheers!