The data type of the month column is not compatible with the sort by value option. You may need to check if the month column is formatted as text or numeric in both the Power Query Editor and the Data View. If they are different, you may need to change them to be consistent. The date table is not marked as a date table in Power BI. You may need to go to the Modeling tab and select Mark as Date Table from the menu. Then, choose the date column that represents the unique and contiguous dates for the table. The date table is not connected to any other tables that contain date values in your model. You may need to create a relationship between the date table and other tables that use dates, such as sales orders or transactions. You can do this by dragging and dropping the date column from one table to another in the Relationships View.