Description:
We observed an anomaly in Matomo reports under Acquisition → Campaigns → Campaign Source - Medium.
- When selecting the period March 1, 2025 – April 4, 2025, the source-medium “bing - cpc” shows 252 visits.
- When narrowing down the period to March 24, 2025 – April 4, 2025 (which is entirely within the first period), the same source-medium “bing - cpc” shows 754 visits.
This seems incorrect because the shorter period (fully contained within the longer period) reports significantly higher visit numbers.
Other rows in that report table (e.g. “google - cpc”) do not show the anomaly described.
Important notes:
- No segments or filters are active.
- The number of rows in the “Campaign Source - Medium” table is small (6 total), so the issue is not caused by aggregation in the “Others” category.
- The Matomo version is current (5.1.1), and no obvious tracking or integration changes occurred during the period.
Questions:
- Has anyone experienced similar discrepancies?
- Could this be related to an archiving issue?
- Could this be caused by the way how visits are attributed to campaigns (e.g. “bing - cpc” overwriting other campaigns in the shorter period?)
- Any other possible reasons or recommendations for troubleshooting?
Thanks in advance for any insights or guidance!