Dropdown menu on top, limits use of Roll.Button on Header slider

Please assist with issue.

I have the menu button that went below the header-slider on a mobile device.
To overcome this problem, I moved the drop-down to the top, and this works well (Z-index).

I am however now not able to use the call to action (Roll.button) on my header slider as it does not show as a hyperlink.

Thank you for your assistance.

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