Hello, @George,
Thanks for the screenshot I have understood your issue.
Now, In order to solve your issue simply go to the Dashboard >> XStore >> Theme OPtions >> Theme Custom CSS >> Global and then paste the below code at the bottom of the CSS box there.
.mobile-menu-popup .et-close-popup{z-index:999999999 !important;}
.et_b-tabs .et-tab{font-size:30px !important; color:red !important;}
Then save settings and check back to your site after clearing the browser cache.
Note: in the above code the word “30” is the size and the word “red” is the color you can change it with you want.
Regards 8Themes Team.