2 Button component not sticking

Hey, this is a common enough query, but I’ve tried everything everyone else has suggested and it still isn’t working. I have a 2 button molecule component I need to stick to the bottom of the mobile screen. It has a simple overlay scrim beneath it of White at 55% opacity, also marked sticky, which does stick. Within the prototype tab, the button component has ‘Overflow: No Scrolling’ visible but diasbled in grey. The scrim doesn’t have this. I’m pretty lost. Any help would be amazing!
Thanks,
Alan