CSSU + forced rotation

When the phone is locked and I press the power button while holding the phone in portrait, the lockscreen rotates to portrait. However, most elements of the lockscreen are misplaced (e.g., background is weird, the slider path is not located at the same place as the slider). Happens with all themes (take the stock themes for example).

Sorry if the problem has already been discussed and solved. Great if you could direct me to the discussion.