Hi @kinectdigital,
You can add some custom css for this, something along the line of this:
:root {
--ag-form-z-index: 100000;
}
Failing that you can target your header when age gate is open:
.age-gate__restricted #main-header,
.age-gate-restricted #main-header {
z-index: 1;
}
Swapping #main-header
for your header css selector.