When a new hire try to complete his paperwork during the data collection step in Onboarding 2.0 he got empty values for picklists.
SAP Successfactors Onboarding 2.0
Set the visibility for mdfSystemExternalUserVisibility as Yes. The Step-By-Step is available in Configuring Picklist for Custom Data Collection
picklist, custom, no, value, onboarding, 2.0