Markup tool fail to save second and more drowning PDF file .

Hi . I have a problem with markup tool and, when I’m using markup tool in Outlook on iPhone and open an attached PDF file, when I’m closing and click DONE button in Outlook The markup tool it only saves first modification and not all of the modification done to the attached pdf file ( for example if I’m open a PDF file which is attached to the Outlook email and I want to sign that file using my finger with markup and if I want to sign in 2 places after I am closing the markup tool and click DONE on PDF file, it only saves the first signature and not the second to). Tried with picture attached and worked fine .Any help please ? Thanks .