I think once Foxit adds any marks they are there permanently. highlighting, underlining, comments, bubbles, 'rubber stamps' (approved, draft, confidential etc.) and more, all removable any time.

I abandoned Foxit about a year ago and use PDF Xchange Viewer which is much better, also free, small, portable and has far more features enabled without adding nagware - e.g. A pro version is available with additional features. The standard installer version of this program from the Foxit website is bundleware, adding a hard-to-remove browser toolbar. Version note: Foxit Reader Portable is the version of the program. Includes PDF Standard 1.7 compatibility, support for the Adobe Portfolio format, Sharepoint integration, as well as command-line features and various signing tools (for both physical signatures and digital via DocuSign). Can insert images, bookmarks and files (including audio and video). Annotation tools include text 'sticky notes' and standard text boxes, as well as form data import and export. The interface includes text reading, two page view, rotation, autoscroll, text view, skins, measuring, text and background color replacement and supports drag-and-drop.

Foxit Reader is a fast PDF viewer that includes annotation capabilities, Javascript support, interactive form filler and built-in text converter.

Install foxit phantompdf