Several WBS element on level 1 not allowed

Hello All,

As per the business requirement, we went for development to create estimates via PS

The client is using this developed estimate process for the last 1 year it working fine. More than 50 plants are using this estimate process. Based on plant code projects are created

Recently we got an issue for one plant where we could not able to resolve the issue

While creating the estimate from z-T-code we got the below issue. We get this issue for only one plant other plant projects are working fine

Error: "Several WBS element on level 1 not allowed"

When I tried to create from cj20n it is working fine it is creating at level 3 as per our hierarchy structure but when I create from z-Tcode we got this issue

Abapers debug the issue but they have not given any solution. They identified that wbs is creating at Leve 1 instead of level 3

Do we have any WBS hierarchy reconstruction program

Please help me with this. I have attached the screenshot

Thanks

Praveen