Hi everyone,
We are experiencing a bug in Looker Studio affecting the YoY/MoM comparison percentages on our Scorecards, specifically when using manual calculated fields.
The Issue:
The base metric calculates perfectly (e.g., a custom CVR field using Conversions / Sessions). However, when we enable the comparison date range (YoY or MoM) on the scorecard, the percentage change displayed is completely incorrect.
Example Data: In one of our client reports, the underlying metrics increased significantly, and the actual CVR improved, but Looker Studio shows a massive decline:
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Signups: +210.7% YoY
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Sessions: +111.2% YoY
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Actual CVR (Previous Period): 3.92%
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Actual CVR (Current Period): 5.76%
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Mathematical CVR Growth: ~+47% YoY
What Looker Studio Displays: Instead of showing a ~47% increase, the scorecard comparison shows -52.7% YoY.
Our Hypothesis: It appears the comparison calculation might be mixing up the periods—for example, dividing the current-period numerator by the previous-period denominator, resulting in an invalid comparison percentage. We are noticing this across multiple different reports, so it is not an isolated incident.
Has anyone else encountered this issue with calculated fields on scorecards? Is this a known bug, or is there a specific workaround required to get the comparison percentage to calculate accurately?
Thank you for your help!