Thanks for your feedback Strainu!
After carefully reading the docs I finally figured it out: you need to fill
*all* the fields. This was not obvious to me, especially since I don't use my full name anywhere in the wikiverse.
Yes, WikiContrib uses the "Full Name" field to allow searching through the UI when multiple contributors are being queried. Essentially any arbitrary name can be given in the field in case you don't want the real name to be given. But you are right, we should notify the user when required fileds are missing. Please file a bug on the repo https://github.com/wikimedia/WikiContrib/issues (preferably) or on Phabricator.
-- Suchakra