We are not sure what you have in your workbook to answer accordingly. But hope some these questions will help.
1. How do you identify the items whether they have exceeded the SLA? Maybe you have a separate field by which you are able to identify them.
2. Is this field added as a filter in worksheet 1?
3. Is the same filter also applied in worksheet 2?
Kindly attach a sample workbook so that it will be easy to understand what calculation you are using and whats going wrong.
Will be able to solve it