Reviewing the Changes tab, I have seen that they removed too much info, including the end tag.
In doing more of them, I am seeing that some of the problems are also occurring because the 'references' tag is entered and later lines are using the 'ref' tag, so they do not work until the 'references' tag is moved after those items 'or' moving the 'ref' items above the 'references'.
Maybe that is another idea for a challenge, but hopefully, most will get resolved from this one.