In Qlik Sense the chart legend is sorted by alphabetical order or numerical order.
Dimension values with no underlying numerical value will be sorted alphabetically. The dimension sort order does not affect the legend.
Resolution:
Chart legend sort order can be customized by enumerating the dimension values.
The interval values can be enumerated by using the Dual() function. In this example, the lower limit of the intervals could make for suitable numerical values. With a mapping table, the legend enumeration only needs to be maintained in one place.