In the screenshot, you'll see a cobwebbed ruin with a stack of spiders in their lair. On the same tile, is Umbers hero hanging out. No combat, no claiming of goodies, it's just stuck there for multiple turns playing with the spiders.

Also, towards the bottom you'll see Umber with two stacks of NPC armies, stacked on each other. They have 0/2 moves and have not moved for 5 turns that I watched them.

Also notice there is a dark wizard tower in Umbers territory. The dark wizard is wandering around and left its tower unguarded. Umbers sovereign is able to roam around and I watched as the sovereign walked through the dark wizard tower and NOT pick up the goodies.

I've noticed the AI sucking major eggs recently and it's not a wonder if it's unable to pick up goodies in certain situations or its armies are getting stuck.