In other maps also, Pannonia is inhabited also with "Pannonian Slavs". It may refer to recorded Slavic tribes in that area, like Vilci, Bodrici, Severani, Timocani etc. In some maps they are identfied as Slovenes – Karantanians (in older historiography, Slovenians consider Great Morava as their state)) or Pannonian Croats.
Also, term "Sclavi" was popular in international communication, even in XIV century, Serbian tsar Dusan in scripts written by his Roman writers is „Sclavonie Imperator“.

To my knowledge, Pannonia was Roman province stretching across today's Hungary, Austria and Croatia. Who were original actually inhabitants of this lands? Was there such thing as Pannonions? Were they Illyrians or related to Illyrians?

Anyway, interesting region. Very old and apparently quite unique looking compared with other parts of Europe.