Manuscript fields like synopsis, notes, rich media, etc. will not save if you erase all its contents.   I typed a synopsis and then decided to delete it, but found it returned every time I cleared the field. Backspacing or deleting a portion of the synopsis worked, but doing so to all of the text will not save.   Further testing shows the same seems to be true of every text field I could find (sans the actual manuscript). The main issue is the rich media field, since even having a blank space there will add the rich media icon to the chapter.   If relevant, I'm using Vivaldi browser (chromium-based).