Hello,
1) Place theme transaltion (XStore core plugin) translation to wp-content/languages/themes (wp-content/languages/plugins) folder, not to wp-content/themes/xstore/languages (wp-content/plugins/et-core-plugin/languages) folder! Then you won’t lose your transaltion after theme and plugin update. It mentioned in our docs https://xstore.helpscoutdocs.com/article/30-base-theme-translation
2) Did you change any images/code in the parent theme folder directly? Use child theme for these purposes. Never change parent theme files because you always lose them after theme/plugin update.
If you need help with the child theme creation provide us with WP Dashboard access and we’ll help you.
Regards