PNG image not displaying properly after applying "size and position" filter

after applyig “Size and Position” filter to clouds.png image, size and position filter works fine but this png image is displaying with a black(shadow). After exporitng video it still display coluds with shadow. I don’t know what’s happening ! please help me.!

My guess is that the scaling operation on the PNG is distorting the alpha channel. Here is a suggestion to try: resize your PNG outside of shotcut to be 1920x839. Then, use the size and position filter with the “fit” option. If you do this, then no scaling should occur, and hopefully the shadow will go away.