In the previous update before scaffolding was added to castles, you were able to vault through these man-sized windows in the castles and walk straight through them. With the new experimental update, you cannot vault into them anymore, and there is a clipping issue where your character cannot actually walk through the opening without proning through it.
Here is the latter half of the issue in video format: https://youtu.be/_PZtdVygHXw