If Statement With Two Tables

Very hard to understand the requirements without sample data and expected results, and there is no indication of what the evaulation context is here. Sample data would be great. Without that, the only thing I can suggest is wrap both SUM() functions with CALCULATE() and see if the context transition gets you what you need. If not, provide data please and expected results.

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How to provide sample data in the Power BI Forum - Provide data in a table format per the link. Provide expected output using a screenshot of Excel or other image. Do not provide a screenshot of the source data. I cannot paste an image into Power BI tables.