Inconsistent results when using Merge Queries

I'm having an issue where I get different results when I create a dataset with certain steps such as filtering out data and sorting, delete the steps, and recreate them again. Sometimes rows are left out and what I have in the Power Query screen doesn't match when I create a table in the report. I have had one line of data with an amount of 350 and if i create a table in the report and have it do a summation, it multiplies it by 2 and displays 700. This multiply by 2 happens randomly to other numbers in the same column as well. I have rows appear and disappear and the number multiplied by 2 go back to what it should be when the only change i do to a dataset is sort the dataset by date. Please advise!