Since updating to WordPress 5.6 all my websites have a side scroll bar on the bottom. It is probably an Elementor issue but thought of asking here as well in case it was something with the theme potentially (only seems to happen when a section on the page is set to “stretch”.
looks like the entire site is built with Elementor – so the issue would be Elementor related.
I notice that you’re using the Stretch option on the Elementor Sections – this uses JS to do that. Instead i would recommend using a full width content container on the page to remove that problem: