Albums have suddenly started to behave strangely.

Interesting, well I have got plenty of storage space, maybe a conversion to FLAC. I think I will try rebuilding my library gradually with only FLAC albums to start with to see what difference that makes regarding duplicates. Mind you I still don’t see why I should go to all this trouble to cover up a problem introduced by SONOS last September / October before which my library was fine.

Playing with the FLAC encoder to get the best results at the lowest size might be fun, no need for CD depth and rate.

A bitrate matching the input stream, not higher would help size. Not sure how that works with VBR inputs though.

Not sure about bit depth, and too lazy to look it up, but matching there could also help size.

Another "no clue" idea, will left/right or center/difference stereo encoding make a size difference.

Enabling the FLAC compression at the highest level would help too, that slows only the encoding process as the decoding remains fast at any compression level.

Thanks for that. To be honest I've seen those settings but just decided to go with the default settings. I will investigate further if I decide it's worth converting some MP3 files. My plan is to just leave all the FLAC files in the library first and see if I end up with duplicates at that stage. Obviously if I still get duplicates then I will know not to bother changing the MP3 files. Just to confuse the issue some FLAC file seem to have different versions of codec such as libFLAC 1.3.1 20141125 or libFLAC 1.3.2 20170101.

Different versions but the format is a standard, RFC 6939, so all modern, post 2001, versions interoperate.

https://www.rfc-editor.org/rfc/rfc9639

All .flac, same rip source, same codec settings and compression still produces random, moving duplicates... Don't waste your time!

Thanks, actually I’ve already decided not to waste my time. I’ll just put up with poor quality software by a company that couldn’t care less about its customers.

Useful information even if it isn't what we hoped to hear. 

I get the feeling there is a low skilled programmer involved, poking at legacy code they don't fully understand.

Reminds me of me when I got handed a pile of data with some ancient legacy COBOL code and told to stuff it into Oracle and convert it to SQL and c. One huge learning curve, but at least I knew not to mention COBOL in the resume I was typing alongside my code.

Exactly.

I have the same problem.

I also have the same problem and I try to approach it philosophically. One day it will be fixed, or possibly not. A while back I noticed that albums by the band London Grammar had completely disappeared from my library (but were still available via folders). My fix was to remove the word ‘grammar’ (using mp3tag I changed them to London G) and got them back. I tell this tale simply to illustrate how some of the Sonos updates do weird things. I have undone those changes and still have London Grammar in my library. I have a compilation album called ‘Bringing all back home’ that shows up in two duplicates, every track,  before and after  Bob Dylan’s album of the same name. I also have instances exactly of the sort being described here. In more than one instance three duplicates of the same album, with only one track. They show up as they should in folders. It is very frustrating until I summon the energy to be unbothered.