Hello,
Header Builder > create a custom header and set it for the Home page, then enable the overlap and change background color.
This https://prnt.sc/A-05RmoAqCK5 should be like this https://prnt.sc/wCQmPZXWJOzN Try to disable all the third-party plugins (including cache plugins), that do not come bundled with XStore https://xstore.helpscoutdocs.com/article/36-included-plugins , clear cache of browser, and check bg settings then. Maybe one of the additional plugins is a reason for the problem.
Regards