[Foodstamp]

This bug happens with MA Oceania Capricorns that sneak from water to land as well. Their land form loses the hiding ability so they are stuck in the province unable to move but also not initiating any battles. You can bug it out and make them attack the province by selecting the commander and clicking around until the order changes from hide to defend (If I remember correctly).

BTW, that is an impressive gear set up for an AI controlled champion!