User role name need to contain "Customer Success"

Hello all,

I trying to create a validation rule in account, there is a lookup field on user in the account and the validation rule need to check if the user I choose is in the role of customer success (by contain because ill have customer success- USA / Europe and etc.)

This is my validation rule - 

(ISNEW() || ISCHANGED( Landing_page__c ) || ISCHANGED( P_P_NDA_Eligible_Cohort__c ) ||ISCHANGED(P_P_account_status__c) || ISCHANGED ( P_P_Owner__c )) && ISPICKVAL( P_P_account_status__c ,"Ready to engage practices") && (ISBLANK(Landing_page__c) || ISBLANK(P_P_NDA_Eligible_Cohort__c) || ISBLANK( Project_Lead__c ) || ISBLANK( P_P_Owner__c )) && NOT(CONTAINS( P_P_Owner__r.UserRole.Name ,"Customer Success")) 

Without the last line its working perfectly, but with the last line the validation rule doesnt pop up (and i choose a user that isn't in the role of customer success)

Any suggestions :)?

Thanks,