[Huz-Z]

I presume that you have checked the tray that is visible in the back window? It raises up via two knobs near each trunk lid hinge to make more room in the trunk. But when you do that, the tray occupies the same space as the lowered roof so the roof will not lower. Make sure that the tray is in the lowest position.

(A Hail Mary, here I know, but worth a try - good luck!)