I couldn't find any answer in the forum regarding my issue to I decided to ask for help. I have some custom html with css class and I simply use the return key to add new text, the whole ul list is deleted( see attached file).
To use it select HTML mode as the file is in HTML. Then change to text mode to be able to edit it. Put the curser at the end of the last bullet of the list then enter. The whole UL will be deleted.
Does anybody knows why this is happening?