Last night in the Non-CP Campaign (PC NA) I experienced a bug where I could walk through the gatehouse at Rayles while the door was fully intact.
Clip demonstrating the issue after the siege:
https://streamable.com/8zngak
This wasn't an issue of being knocked into a wall by a leap or a similar skill. I was able to walk through the wall as soon as I arrived at the keep door.
Nobody with me was able to recreate the issue. I did not try to recreate this issue at any other keeps.
Bonus longer clip:
https://streamable.com/gwl811