Comments on lines of code disappear in a review when highlight lines are edited

In Crucible 3.7.0 and 3.8.0, I can reproduce the following behavior in Safari and Chrome web browsers:
1. Create a review comment highlighting several lines of source code.
2. Edit the comment and change the source highlight, click "Comment" to save the changes.
3. The comment disappears.
4. Creating a new comment on the same range of source lines will briefly show the original comment. Reloading the page will show the comment again.