Because stamping is a comment signature, there will be unknown errors in printing and problems in analysis.

The signature of the annotation can be moved at the point source, so it should be annotated in a plane, so that the seal can not be modified by the annotation and can not be moved, so that there will be no cross.

You can also "Open PDF- Toolbar-Edit-Preferences-Signature-Verify More, and uncheck the signature when opening the document".