Hi @paj324,
There are a number of areas that need/can be checked for sorting and may be affecting this from filtering correctly although that is hard to see with small zoomed in screenshots of your columns. Are you able to create a copy of your analysis and share in the Arena view?
Additionally, another work around you could test out..create a calculated field that ranks your commission based off the aggregation levels being used in your pivot table. You can use the rank or denseRank function.
Then, setup your visual to be sorted by an off-visual field and use the newly created rank field to sort.