Hello,
The same situation happens even with the default theme https://gyazo.com/3c9f67cb84b6795d0512d27c2edbc223
So, XStore is not the reason of the issue. Check the plugins that you use. Besides, did you make any changes in parent theme files (I see that you display selectors on the grid and custom styles of the buttons)? You will lose the changes after the next theme update! So, enable child theme and move the changes you need to child theme. USe child theme styles.css to add custom styles you need, but don’t copy the whole CSS files, only styles that you want to change.
WordPress released 5.8 update and we’ll release theme update soon that will support WP 5.8, so you will have to update theme and I’m worrying that you will lose your work.
Regards