Iron Golems spawning partially inside other blocks, including glass, stacked slabs, and other solid blocks such as iron blocks.

The Iron golems are spawning partially within solid blocks, often unable to move freely.  They sometimes take suffocation damage, and sometimes they can be pushed through the block and out the other side. 

 

They also seem to be spawning on glass blocks and on blocks that are in the middle of a wall (so also partially inside a higher block) making them appear to be climbing the wall.