Add background action bug

[chdcomputers]

I am using clawPDF to auto save single page printouts from another application.
I add a pdf background and the resulting pdf renders fine.
However, if I open the final pdf with a pdf editor (for example inkscape) I can see that the content of the page have been rendered twice with the second render to overlap the first one.
That doesn't cause any visual problems since the second render is at the same position with the first one however I am using a pdf text extract utility to post process the file and it outputs duplicated text that causes issues.
I should mention that the whole page (including the background) gets rendered twice. It is happening regardless of the repetition setting.
And of course it is increasing the resulting file size because of the duplicated content.

Thank you.