I hope this is not a dumb question, but I seem to have a problem with Sonos not being able to read certain M4A metadata, namely Album and Title.
I use a little external hardrive connected to a Fritzbox as a poor man's NAS. The NAS stores a copy of my digital files and is hooked up to my Sonos system. The formats I use are lossless FLAC, MP3, M4A from iTunes (all of them bought in the store) and self generated M4A (basically I am ripping audio from a streaming service as a speed up workaround to digitize my records).
I would say 99,9% of my files have good tag quality.
Sonos reads tags just fine from everything EXCEPT the self-generated M4A files. There I only can find an album by browsing through the folder structure. And if I have several albums from an artist, they are shown on a flat level. It's a mess.
The strange thing - when I change tags from my itunes m4a collection via mp3tag, the changes are reflected just fine in Sonos.
Probably this problem is a Sonos issue (foobar, vlc etc.. read the data just fine too), but before I contact their support I wanted to check if anybody in this forum had this experience before.
Or is there a possibility to completely regenerate the m4a wrapper? If possible I would like to avoid a further transcoding.
Thanks for your thoughts and advice!