Hi @colsmith,
if I understand you some users with JOBTITLE_2__c valued and other without.
In this the first control is check if i workday are present those values for the users they miss.
Make a soap call for those users an see if the values and the key are present in the integration filed section.
The mapping of integration filed in SP, sometime could be a problem because those attributes are not properly standar attribute in workday.
Also, if those attributes are not build correctly (in WD) the mapping with __c, fails.
You can try to mapping with the xpath. In this topic I explain a little how do:
but first of all, check the data in workday with soap