I think someone else had the same issue, but my Soundtouch wont show recently added music from itunes!
They are definitely AAC files and definitely unprotected, but the only way I can seem to get it to update is to remove the itunes library in the Soundtouch app and then add it again.
I have had this same problem for 2 months and even with the firmware updates etc it doesnt seem to have solved this.
Can anyone help? For info using Lifestyle 600 and itunes version 12.6
Thanks!