Hi @utrautmann, thanks for the detailed report.

I've worked through those steps to try to recreate the issue using the same date as your example on demo2. (https://demo.matomo.cloud/index.php?module=CoreHome&action=index&idSite=1&period=day&date=2022-05-01#?period=day&date=2022-05-01&idSite=1&category=General_Actions&subcategory=customdimension2)

The page authors listing shows 1,519 actions and 1,263 unique actions.

In the export file I get 1519 hits and 1,263 visits. I didn't see the 1,100 entries as visits, if you can still see this value could you provide a screenshot?

The pie chart is showing 1,247 unique visitors.

Unless I'm misunderstanding the issue, all these value look correct.

There were 1,247 people who visited Julien's pages (nb_uniq_visitors), some of these people made multiple visits (same visitor returning >30mins since the last visit) so there were 1,263 visits (nb_visits). During all these visits Julien's pages were viewed 1,519 times (nb_hits).

How visit is defined
How unique visitors are counted
What is a hit in Matomo

I hope that's helpful.

Hello @bx80 , thanks for your explanations.

I think there is really a misunderstanding between us.

You exported the custom dimension values to see the number of visitors.
However, I selected the visitor log for a specific value ("Julien") from the custom dimensions and counted the entries there with an export. And this is where I see differences.

The visitor log has fewer visits than the export from the custom dimensions (when I compare it to nb_uniq_visitors).

To the background:
I noticed this when I created a new custom dimension (scope action) in another project and it was actually only 2 unique visits according to the visitor log that triggered a specific action value in this custom dimension.
Although these had triggered the relevant action several times, there were only two unique visits.

However, the custom dimension export and pie graphic showed me 4 nb_uniq_visitors.

And so I went in search of whether there were any differences in the demo platform. And they were.

Thanks for explaining this in more detail @utrautmann, my mistake I was looking in the wrong place. The nb_uniq_visitors for the custom dimension should be matching the number of rows in the exported visitor log for the segment. I'll mark this as a bug so our product team can prioritize it. 👍