Users get access to directories they shouldn't

[NicerDicer 3]

I have a library "Series" with the directories "Shows" and "Shows.Incoming", both containing subdirectories like "Show name". Access to the Incoming directory is explicitly removed for regular users (unchecked). I put new files into "Shows.Incoming/Show name/" to check them without regular users seeing them, before later moving them over. That worked fine until recently, when files there started being accessible for regular users regardless of that removed access to anything under "Shows.Incoming".

[NicerDicer 3]

Addition: This doesn't happen with "Show name" directories that are only in "Shows.Incoming" and not in "Shows", just with files in "Show name" directories that exist in "Shows.Incoming" AND "Shows".