Most likely cause: the value being assigned isn't a valid choice on sn_customerservice_case.contact_type, so the form renders it as --None--. Out of the box this field does not ship a "Portal" choice — typical values are along the lines of phone, email, web, chat, social (verify in your instance, as choices vary by release/plugin).
Try - Fix:
1. Confirm the choice exists. Go to System Definition > Choice Lists, filter table = sn_customerservice_case, element = contact_type. If there is no portal choice, add one with Value = portal (lowercase, no spaces) and Label = Portal — or reuse an existing value like web.
2. In the record producer's Script field, set the stored value (not the label):
current.contact_type = 'portal';
3. Check that no business rule on sn_customerservice_case (insert/before) is overwriting contact_type after the producer runs.
Quick test: open the created case in a list view to see the raw stored value — if it's blank, the choice doesn't match.
