Validations to check for Employee Element Eligibility

Hi, i'm trying to create a program that does the following:

1. Get Details from Custom Staging Table
2. Validate Details from Custom Staging Table
3. Create a Secondary Assignment for the Employee( Assignment Number: XXXX-2 ) with some changes (i.e. Pay Basis and Payroll).
4. Switch the Primary Flag from XXXX to XXXX-2
5. Terminate the Initial Assignment (XXXX)
6. Carry over all elements that are from the Previous Assignment.

So far I was able to do steps 1-5 successfully. However, for step 5, i'm encountering an issue for some elements only, namely "Flexible Holiday Plan" and "Regular Salary"