Looking at the screenshots, the first thing I notice is that you don’t seem running the latest version of the CSS. Make sure you update to the latest.
I am not able to reproduce the issue on my side so I am wonder if perhaps you had Sliding Panes turned on before? Sometimes Sliding Panes doesn’t properly remove its classes and can cause some issues. Try restarting the app. Alternatively is it possible that you have a table or wider element lower on the page? Wide tables can sometimes cause an issue like this.