Goodday, I encountered the following problem – when adding a product to the basket from the product page, the value of the total in the header of the site (where the basket is) is not updated (only after the page is reloaded). Why can this happen?
Please deactivate all the plugins not related to the theme and switch the parent theme, check the issue, if the problem remains, leave the plugins not activated and provide the site admin access to the private area
The problem may be caused by a custom code that you added to the child theme. Please check all your snippets, disable them one by one, and check the issue to detect which snippet causes the problem.