Settlement rule

Hello Team,

I had a operative project with below structure

C-XXXX

C-XXXX-top WBS

C-XXXX-10

Network

Internal activity 1

C-XXXX-10.1

C-XXXX-20

C-XXXX-20.1

Internal activity 2

Internal activity 3

C-XXXX-20.2

I had use above project to create new project. For new project,auto settlement rule for activity not created WHY?

If I move activity 2 to WBS C-XXXX-10, settlement rule created WHY?