Hi,
Thank you for reaching out!
We have got the issue you have mentioned here. It is fixed on our demo. Please add the below code to fix it on your end also.
Add below code at Appearance -> Additional CSS
.site-header {
position: relative;
width: 100%;
z-index: 99;
}
Secondly, the sidebar menu only show till the 1024px media. After 1024px menus will be appear in a line.
Let us know if you have any questions or concerns.
Thanks