I am trying to convert all of our client spaces from Kanban, which is also team-managed, to a scrum board that is company-managed.
I started out by:
1) creating a new scrum board with the client name and selecting company-managed
2) going to the old board with all the tickets
3) Selecting List view
4) Select all filters and then bulk move everything after mapping to the new scrum board.
I realized that some tickets are not showing up, even with all filters turned on. If I click detail view, I see many more tickets, but I am still not confident that I am seeing EVERY ticket in each client space. I want to feel comfortable deleting the old boards once the scrum board is created and I have moved the tickets over.
Has anyone had experience with this that can provide advice, or is there another process that is safer and less time-consuming?
One screenshot I provided shows to-do, in progress and done checked, but only 1 ticket is showing. Another screenshot shows the number of tickets that show if I click Filter, Basic and then Parent (19) and then if I click "detail view" on the right it shows 18 tickets. 
