Hello,
The Gantt filters are activity filters, so they apply to activities only.
So we no longer see milestones, meetings and the like.
You just see the parent projects.

Hi,
This is something I can understand for meetings.
But, in a Gantt, milestones and activities are at the same level of importance and are both fully part of the planning.
Therefore, they should be filtered in the same way.
Best regards.

Yes, but they are not the same class of object.
So they don't have the same fields...
So filters cannot be common (a filter on duration has no meaning for a milestone)...
We had to choose one class for filter on Planning, and we choose Activitiy.
Now, filtering on several classes may be possible, but is much more complex and we did not invest on that side.