Hi,
this drives me crazy so I am trying my luck here.
I have several classical scrum projects and 4 next-gen kanban projects. I have created a filter, where I query all actual tasks across all the projects (and it works well, I can see all tickets in search result).
But when I create a board based on the filter, tickets from the next-gen projects are not there (I mapped all the statuses to columns, this should not be a problem).
The weirdest thing about this is that tickets from two next-gen kanban projects are there, but from 2 newer ones are not. Both next-gen projects which work are several months old, those who do not work are about 2 weeks old.
Any tips? It limits us a lot 
Thanks
Tom