We recently upgraded to Bitbucket Server 7.0.1 and are now experiencing issues.
Sometimes, a pull request diff will contain files that are actually modified but the changes doesn't appear in the file viewer.

In this screenshot, the line 10331 contains the actual change, but the line is not visible.
Also, note that there should be a bottom line showing "..." (like the line on top of line 10321) that you can click to inspect the code further down, but it is not present.
We've seen other issues in pull request like diff showing changes that are actually already in the target branch, unfortunately I don't know what causes some pull request to flag code as changes where this code is already present in the target branch.
I have read the blog post A better pull request, particularly the "Logical conflicts that merge cleanly" part, but it doesn't seem to be related to the issue we're experiencing.
Any help is appreciated.