Exclude Fix-term and front-office eligibility profile

Hello,

We have been trying to create an eligibility profile for the Onboarding that includes only the back-office employees and excludes the contract type: Fix-term contract. We used the predefined eligibility criteria for the assignment category "Back-Office" and a fast formula for the exclusion of the fix-term:

'DEFAULT FOR CMP_IV_ASSIGNMENT_ID IS 0

DEFAULT FOR PER_ASG_CONTRACT_TYPE IS 'N'

 if (PER_ASG_CONTRACT_TYPE = 'FIXED_CONTRACT')

  THEN

  (Eligible='N')

RETURN Eligible

Yet all the population was getting allocated the tasks, regardless of their contract type or assignment category. Backoffice, front-office, permanent contract, fix-term contract, everybody was getting allocated. Later we tried to use the predefined Assignment Category "Front-office" and flag the exclude option, but still the same results.