I now only see the individual file diff, not the listing of files which used to be where the orange "CHANGES.md" is now.
Moving the grippy to the right of the sidebar does not help expose the file listing nor does tinkering with the "Pending files, sorted by path" setting.
There's a recently opened bug ticket SRCTREE-8143 that I found in the support forum that describes the same issue.
At this time, according to the ticket, the workaround has been to downgrade to version 4.2.7