From project catalogue, for each project, we can see only one project manager and other members.
If there are several project managers, they are listed as members.

In that case we can think that there is 1 responsible and 19 members (20 persons) but on this projets there are 21 persons (19 members + 2 project manager --> David and Julien) .

This bug appears as soon as there are several project managers.