Possible mismatch Activity Dashboard and Contributions list for subgroups

When looking at the Activity Dashboard in your profile page (e.g., https://gitlab.com/bikebilly), you can see the colored squares that shows how many contributions you did. Clicking on them, you can access the list.

I found a strange behavior: if I comment an issue in a subproject, it will be listed but it will not be counted in the dashboard. Could be any other reason, I just did a quick test.