In the WYSIWYG field, there are times you have to use the Text Editor rather than the Visual Editor. It is still superior to the standard code editor because clients can still highlight and bold and italicize and link and not have to worry about paragraph tags, but when the editor switches to Visual, it breaks the code if there were some non-standard things. An example of this is adding text in between list items (text

text

). Normally this isn't an issue because once the editor is in Text mode, it doesn't switch unless you tell it to. But after 2.8, that's no longer the case, now after each page refresh, it reverts to Visual Editor and breaks that previous code, so you have to re-do whatever you previously did every single time you want to edit. This is mainly an issue in WooCommerce pages if that matters.