There is a silly high z-index on the hamburger of 99999999
Maybe it’s controllable in that stacks settings?
If not…
Add this css snippet to your page to boost Frags z-index to trump it :
.stacks_in_796_page9dooimgs-grid-doomodal{
z-index:10000000000 !important;
}
Note this will only work for this instance of the Frag stack, as it incorporates the stacks id, which is dynamically generated and different for every instance of a stack you deploy to a page.
I may bump Frag to 2147483647, the highest z-index can possibly go.