Hello,
Please, update theme to the version 3.12. It’s available on ThemeForest.
Do the backup of theme options before the update (Theme Options > Import/Export > Options > download .json file)
After update disable XStore Core plugin, re-activate theme, then activate XStore core plugin and go to Appearance > Install plugins > update Core plugin.
We have made some improvements for the cart/search/wishlist options in the header https://www.8theme.com/demo/xstore/update-history/ so, after update very likely you will need to choose the position of these options in theme settings.
Regards