Dear @Maze
this is correct. When the cover is activated, then the Ninja-Forms does not work anymore.
You could try to use CUSTOM CSS to build the cover feature yourself.
Give the first row a window-height:
0_1526891576667_Bildschirmfoto 2018-05-21 um 10.32.20.png
And then add that code:
._100vh .background-image {
position: fixed;
}
.row {
background: red;
}
Please not that this code is just a rough sketch. You might need to do some adjustments.
But that would be a workaround.
Hope I could help!
Marius