Hello,
1/ It is a known problem of WPB, when you open an element like this the first time, and want to change between mentioned tabs, you need to close settings of the element and then open one more time, then it will work https://gyazo.com/04f4b2fef6e3a38f94df8094f9713d19 . It is independent of the theme, so can’t be fixed from our side, unfortunately.
2/ We did not test XStore with that plugin officially, so can’t give a solid response, right now. You can leave the request here -https://www.8theme.com/taskboard/
Regards