PowerBI framework loves to aggregate data. This means that duplicate values are transferred to visual only once. Usually, this is the right thing to do, as many times it doesn’t make a difference for visualization. Aggregating data has a positive effect on performance.
When using Control Charts, aggerating has to be done in the visual, in order to get correct results. That’s why it is mandatory that data comes to the visual in the correct order and correct granularity. Best way to achieve this is to use Row Id.