when editing a pdf file in inkscape, it is not possible to place an object below the PDF text. how to win it?

Perhaps generate a new layer under the current one.

thank you. your idea helped: when dragging an object in a multipage document from sheet to sheet, the object is not dragged from the list of objects of one sheet to the list of objects of another sheet and therefore does not interact with objects on the page on which it appeared. manually dragging from list to list solves the problem. perhaps it should be fixed. but you can live like this