The Month is Sorting by name Like August, October & September because O come before S. But it should sort by Month that is October somes after September.
The workaround is to use a "sort by" column, but I agree... It would be nice if Power BI Designer compensated for a bad model design ;) https://support.powerbi.com/knowledgebase/articles/592116-sort-by-column-in-power-bi-desktop
