I'm using Tableau 10.2.5. I've created a horizontal bar chart using a set for the Top 20, which is intended to show organisations by descending value of income, up to and including the organisation with the 20th largest income. However, I've noticed that the organisation which should appear at position 20 is missing; the organisation which is at position 21 in terms of income appears in its place. Oddly, when I change the conditions for the set to show me the top 21 (instead of the top 20), the organisation which should be shown at position 20 appears correctly and the organisation which was appearing at position 20 has moved to its correct position of 21st. The income values of organisation 20 and 21 are not particularly close.
I wondered whether this is an issue anyone recognises, or if you have any advice about why this might be happening.