DP Lightbox - not centering

Hey - I am trying to create a modal pop up that is in the middle of the screen. I’m sure when I used Axure last time (a few months ago), the ‘Treat as a lightbox’ option forced the modal to be central and stop the background scrolling too? Now I don’t see to be able to!

The file is too big - this is the link https://utjz32.axshare.com . The issue is on the homepage when you hit the ‘Account’ icon (top right, second in from edge) + switch to ‘Join now’ link.

Hello @beckympb

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Middle, centre

I have the same issue with background still being scrollable.

I have tried that and the background still scrolls, plus on the second state in the DP I can’t ever reach the bottom.