On large screens the sidebar is 28% width. On narrower screen such as mobile the sidebar moves to 100% width and below the main content area.
I have looked at your two sites and they are both displaying correctly. The cut-off point where the sidebar changes is on screens/browser windows with a width of 768px or below, above this the sidebar is 28% width.
768px is regarded as a good value to use for instances like this.
It could be that you have a mobile with a screen width larger than 768px? This would explain why you see the larger screen layout.
Are you viewing both sites on the same mobile device with the same browser?