When the pdf of a content is replaced, memo will be carried over, but bookmark and marking data will be discarded.
When the total number of the page varies between the previous content and the updated one, then the position of the attached memos also be affected, and need to be modified.
Only on the iOS app, marking data on the previous content can be copied to the new content by "Copy the all marking data" function.
Please refer to the following manual for more detailed information.
【Web】5.4 Attaching Memos> "▼Moving or copying memos"
【Web】5.14 Copying Marking Data