Ok… I found the issue. There is a bug on Fibery when importing templates.
At the beginning we created come Spaces for different Users and on several of this Spaces, we imported the Project Management template. It seems that Fibery doesn’t rename the DB names if one already exists with the same name when importing a template. So on my User Fields, there were several relations to different Tasks DB’s with the same name ! When I copied your formula to my field Tasks Joined, it pointed out to the wrong Task DB.
I renamed all the Tasks relations to clearly identify which Task DB I was using on my formula and now it works !! ![]()
Many thanks for your help, I learned something today !