Movie behind the transparent picture is black

I have a problem with rendering of movie (imported as plain) behind a static transparent picture with alpha (also imported as plain with alpha enabled) in Cycles.

Everything looks OK in Material Viewport Shading:

The problem becomes when I switch to Rendered Viewport Shading or when I want to render the final video. If the camera stays before the transparent picture, the movie behind the transparent part of picture is black:

The movie becomes visible when the camera moves forward cross the transparent picture and stays directly before the movie and the transparent picture is behind.

How can I manage the visibility of movie behind the transparent png?

I found it. Just easy solution. It needs to set the transparency also through the Node editor - not only check “use alfa” function by importing as plain: