Newlines and “read more”?

I tried to search for an answer, but I didn’t quite find what I wanted.

I noticed a change from when I upgraded WordPress. Before, when I used the “more” quicktag on a separate line, it put a newline (paragraph break) between the two lines the more tag was between. Not it runs those together.

Specifically, when I entered:

before before before before.
<!--more-->
after after after after.

It used to print out like:

before before before before.

after after after after.

But now it looks like:

before before before before. after after after after.

What can I change to get it back to the old way?

Thanks in advance.