None of your settings should change anything, but they might detect it (for example, the hashing might detect changes due to bit-rot on one side or the other, or changes to content made by indexing software...). Basically, the path to follow is as per this post (not necessarily the whole thread, but you may want to read it for background). You need to determine what values are changing (or are being listed by the PC as different on one side or the other, anyhow) to have any chance of figuring out the cause. We can't see from here...
It's also useful if you mention Fast Backup to say 'which mode' (there are two). If you're using archival (archive bit) mode, that might well be your answer if something (possibly indexing software) is setting the archive bit on files where it added/updated some meta-data (or data in an alternate stream) - in an attempt to get those changes backed up...
It's also useful if you mention Fast Backup to say 'which mode' (there are two). If you're using archival (archive bit) mode, that might well be your answer if something (possibly indexing software) is setting the archive bit on files where it added/updated some meta-data (or data in an alternate stream) - in an attempt to get those changes backed up...