I am finding that if I run an Apply to Each that uses Set Variable, it will seemingly pull the variable value from a different concurrent Apply to Each and mess up the math that is being calculated in any Apply to Each item. The only way I could get math in Compose (uses the variable values) to be consistent & 100% correct was to turn off Concurrency Control. Which, unfortunately, makes my total Flow run time go from 60 seconds to about 11 minutes.
Is this a bug?