Bug with transparent PNG on ATEM Mini Extreme

I get this awful white screen whenever trying to upload a PNG with just a simple transparent drop shadow beneath it. I’ve tried using a mask to get rid of the white, which works, but it’s simply too much since I have 15 more splash screens to put up as well.
Anyone know how I can get rid of it with the drop shadow still being visible? Fill source Media Player 1, Key source Media Player 1 key, pre multiplied key on.
I’ve also taken the time to make the transparency blended with black? I don’t really know what it does, but it’s essentially the same as exporting it to Media Pool via Photoshop.