We have checked your website. At the footer, you have added some reviews with the help brb collection widget (may be with the help of some plugins) https://screenrec.com/share/XVxEqoYBHc. They have applied a with that is applied to mobile view also. We have tried adding our CSS but it is not working you can try by adding the below code at Appearance -> Customize -> Additional CSS
As we have checked the site this is the only issue we have found which is going beyond the body area. 1212px width is added to that section for mobile as well. For desktop it is fine but mobile doesn’t have that much space. You can check if they have some setting related to width for mobile then it will be good.