Hello @Chris_McGolpin
Chris, first the version question, because you asked twice and you were right both times.
The build numbers we quoted, 1496 and 1651, belong to a Roon Server installed on your MacBook Air and to the Roon app on your iMac. Neither is your Nucleus, and both show an empty library, so neither is where your music lives. Your screenshots were accurate all along: your Nucleus and your remotes are on 2.71 build 1683, and there is nothing for you to update.
You have raised two separate things, so let us keep them apart.
The message in your latest screenshot
That one is telling you something real:
Playback notifications are unavailable because the notification permission was denied. Roon may be less reliable when the app is in the background on some devices.
Roon asked your iPhone for permission to show notifications at some point and was declined. So it cannot show playback notifications, and it is warning you that it may be interrupted when it is not the app on screen.
Please turn both of these on:
- Settings, then Notifications, then Roon, and switch Allow Notifications on
- Settings, then General, then Background App Refresh, and make sure it is on and that Roon is enabled in the list
That message should stop appearing once the permission is granted.
The playlist message
Before anything else, one question, because the answer decides whether this is a fault at all.
When you add a track to that playlist, is the playlist one you created in Roon, or is it a Tidal or Qobuz playlist? And are the tracks you are adding from your own library, or from Tidal or Qobuz?
It matters because the two behave differently. A playlist that belongs to a streaming service can only hold tracks that exist on that service. If you add a track from your own library, Roon has to find the matching version in the service catalog, and where there is no match it says exactly what you are seeing. That would also explain why one track was accepted and the next refused: the first had a match and the second did not.
If that is what is happening, this is not a fault, and we will show you how to tell the two kinds of playlist apart so it stops catching you out. If your playlist is a Roon playlist, then something is wrong and we will keep digging.