If I have two browsers (two apps I guess) which are playing some media, there are 2 entries, which are shown in the NowPlaying menu bar item:
however only the 1st one is actually taken into consideration for all BTTNowPlaying variables, which should not be the case, since as seen in the screenshot in reality the second app is playing the media, while the first one is on pause. Also the BTTCurrentlyPlayingApp is also affected.
unfortunately I don't know how to get more than one, this looks like a new feature.
The Now Playing API is undocumented and private, which means it will require some reverse engineering to find whether there have been any new functions that would return multiple playing apps. I'll have a look, but it will take a while ;-(
This is not a big deal, I've just thought that this is a bug, and not that it is caused by a "new feature" by macOS. I have absolutely 0 (even negative 
) knowledge how this works, but I guess the app should report the following - MPNowPlayingPlaybackState | Apple Developer Documentation, if it is irrelevant just ignore me.
Thanks.
unfortunately that API is for media players that want to provide the now playing state to the system - not for external apps that want to read it
I think I found the new function already (MRMediaRemoteGetNowPlayingClients instead of MRMediaRemoteGetNowPlayingClient), but I'll need to think about a way to integrate it.
Hey Andreas, did you fixed/implemented this in 4.867? At the moment I'm testing this version and it seems that it is working as expected.
no, there still is only the one variable (or maybe I don't understand, what does work better than before? I don't think I made any changes)
Hm, the only thing it might solved it is the restart of my MacBook. I have not changed anything as well, hm..