linux – rsync: list only modified files / attributes

I am trying to achieve the following goals:

In order to check if I have correctly synchronized all data from my old NAS to my new one, I run:

rsync –rltD -hvinu / path / to / old / NAS / / path / to / new / NAS

Now: -n give me a list of changes -ia and -u should ignore all the latest files on the new NAS (which I need because there are already updates on the new NAS – people are already working with the latter).

The command above gives me a list that contains this for several directories:

.d..t, who acc. to man-page means that no transfer will take place, but that the attributes (that is, the time) will be updated in the target.

By checking the directory, I notice that the directory of the target is more recent than that of the source.

So, I was expecting (1) to not even see it in the rsyncs output – because that should have been ignored, and secondly: there should never be an update of this timestamp.
-u should take care of that.

Any rsync pro here who can explain? What do not happen here?

By the way: there is an rsync implementation on a Qnap NAS (source) and a Synology NAS (target).