Hi,
just a quick note before we dive into the details: We don't support the direct connection to MacOS officially yet. It works for many people, us included, but Apple hasn't decided to join the Milan initiative (yet) and we thus their interpretation of the AVB standard can change at any time. This is why we cannot guarantee that it works in every setup with every version. However, we try our best to make it work and are in contact with Apple to improve this situation.
Can you please post a screen shot from the web interface's "main screen" and then one with the input streams settings dialog open (open a stream port, click on the gear icon).
My best guess is that the streams are set up just fine, but there's something wrong with the clocking, leading to "lock" but "no sync". Or, if the Mac doesn't receive a valid clock, it won't start playback, so "no lock".
Which MacOS version do you have installed by the way?
And what do you mean by "lose ... channel routings"? Channel routing in the M-1610 web interface? Or *stream* connections in MacOS' ATDECC controller?