This is a super weird bug that I just noticed happening at Caer Lem, and it happens both in and out of combat. In the goblin caves, my characters were not able to move to the squares beneath the "falling cages." Those squares were quite literally not clickable, and didn't even show up as part of the grid during combat. I realize standing under a falling cage isn't smart, but it wouldn't even let me move through the squares, which set up some weird usages of available movement.
Second instance was the movable crate on the second tier of the wooden stairs outside the tower. After my fighter moved the crate aside, the square it moved from was not available as an option to stand in during combat, and after combat, there was a loot bag left over from one of the enemies located in that square and when I clicked on it the character would move to the square, but nothing happened. There was no way for me to pick up the loot in that square.
Neither of these things happened during my first play through before the winter patch, so I'm guessing that the winter update broke something in that regard?