I am seeing something possibly related to this in build 9361.

I open a directory tree in the file browser and have several nested directories expanded showing the files in those directories. Then I close a directory either by clicking on the triangle next to it or by using the keyboard (I am not holding down the option key). Next I expand that same directory. At this point I can see all of the immediate children of that directory, but I cannot see the children of any subdirectories. The triangles next to the previously expanded subdirectories are pointing downward indicating that the directories are expanded, but none of their children can be seen. If I then click on one of those downward facing triangles twice, once to close and again to re-expand the directory, I can now see the immediate children in that directory, and so on.