Ok so I have the same problem. Just using the classic editor the read more tag works. but within the Advanced layout Builder provided by Enfold it does not. Now I have a client attempt to write her own blogs and she has hundreds of articles. I finally, after five years got her to move from wordpress.com to her own site with enfold and well she is not liking the more bar not working. She does not having the training or desire to learn how to do shortcodes or edit in html mode. I found using the excerpt option I can past the HMTL code and it looks good, but that is so much harder for her. Do I really need to tell her to use the classic editor instead of the enfold one which is why I wanted her to change to her own site?