New firmware as of Oct 15th 2025 did not fix this problem:

Modern: Version: 17.5 (build 91.0.70070)
Legacy: Version: 17.2.1 (build 86.1.70070)

--Brian

Brian,

I’ve been carrying out some tests with my music library. First I removed the library from my server (Unraid). I rescanned the library which obviously returned no music. I moved back the library in alphabetical chunks, rescanning the library each time and then checking for duplicates. It wasn’t until I got to the letter L that I saw the first duplicate. After that I returned the entire library. I then did a bulk rename of all folders by adding 01_ in front of each folder. It changed the albums affected but generated two new duplicates. I then removed the prefix from each folder and it returned the original duplicates and removed the two new duplicates.

I keep two separate library’s, one that has normal CD rips and one that has FLAC conversions of 24bit SACDs. When I added the second library back to Sonos and scanned the library every album was okay, no duplicates! It might just be a coincidence. Anyway I’ve left it alone for now.

I see that I’ve now got version 17.5 (build 91.0.70070). I did the tests before the overnight update. Understandably I’m in no rush to change anything on my library at the moment.

One other thing I noticed was that if you search for the artist of a duplicate album it will list the artist multiple times. If you then select any one of those artists it will list all of the tracks in the album but not in track number order, in alphabetical order instead.

Anthony

In UK so 80.30.31/ 91.0.70070 just landed 15th for me. Prior to this update had experienced problems with duplicate albums & albums with no tracks in local library. Interestingly, neither resynching NAS, updating library in Windows desktop app or deleting library and then restoring it worked. As it only seemed to be a few instances I left it and waited for next update, using app only for paid streaming service.

Update yesterday seems to have sorted the local library in terms of tracks re-appearing in empty albums and duplicates disappearing. 

Hi, yes I'm in the UK too.

It's good news if it really has fixed the problem. However as my library seems to be okay at the moment I'm just going to leave it untill I have to add another album.

See quote of CronoCX post below

"CronoCX wrote:

New firmware as of Oct 15th 2025 did not fix this problem:

Modern: Version: 17.5 (build 91.0.70070)

Legacy: Version: 17.2.1 (build 86.1.70070)

--Brian"

I'm a bit of a believer in "if it ain't broke don't fix it". Only time will tell.

I have been in touch with Sonos tech support (Tuesday 14-10-2025) and it was escalated to level two (whatever that really means). I was also told I would be kept informed. I've had no feedback so far. If I do hear anything I will post it in this tread.

Anthony 

Also on build 91.0.70070. I think you may have gotten lucky. I removed my library and added it back. Still have duplicates. It acts the same. Which albums are duplicated changes when adding an album or renaming a folder.

I have also noticed some duplicate albums that were not there a week ago.
Also a single duplicate artist.
I subsequently removed and re-added the albums in question and reindexed and it fixed the issue for me.
I have over 1500 albums so not sure yet if the reindex transferred the problem to other albums.🤔
Ross.

Yes, I’m inclined to agree with you. I did notice that I had library scanning on daily at 23:45. I have disabled daily library scanning. I always scanned the library when I added something new or edited something, so why I had set it up to carry out daily scans I can’t remember.

Yes, that is an issue, actually going through the library looking for another duplicate. Luckily my library is smaller, about 500 albums. I find the duplicated artwork more readily shows up the duplicates.

I re-instated the daily library scan (02.00 hrs) a month ago after disabling it back in May '24. 

Downloaded an album via Presto Music yesterday and after sorting out tagging etc on PC uploaded to NAS and all was good this morning.

Have noticed the visual appearance is a little different on android as was mooted in release notes, all heading right direction. Still await return of HD/Hi-res banners on Local Library material, and strangely the thumbnails have disappeared on queue view on android... but these are rabbit holes best stepped over...

Hey all!

Looks like there might be a fix for this with the latest App update which dropped today. I’m not in a position to test it out though. Of course these options are also in the Desktop App Controller and it was not working there either, so yeah, might  

—Brian

Have done the update but can’t see any change. Went to music library and changed the order but as yet see no difference. It is however encouraging that Local library features are being added. Would still like to see bitrate/file type for local music. 

Hey all!

Looks like there might be a fix for this with the latest App update which dropped today. I’m not in a position to test it out though. Of course these options are also in the Desktop App Controller and it was not working there either, so yeah, might  

—Brian

I don’t have that update yet, but I’ll wait with bated breath. Checked on play store and Apple Store, not showing in the UK.

Mine updated an hour ago from Apple Store

Updated here. Re-scanned. No change. Still have the multiple duplicated 1 track albums. I think the change here was just about adding those setting back in the new S2 app. They used to be there in the old S2 app. They were/are still in the desktop controllers. 

Hey all!

Looks like there might be a fix for this with the latest App update which dropped today. I’m not in a position to test it out though. Of course these options are also in the Desktop App Controller and it was not working there either, so yeah, might  

—Brian

I don’t have that update yet, but I’ll wait with bated breath. Checked on play store and Apple Store, not showing in the UK.

Okay, just updated on Apple Store, re scanned library but it made no difference.

Ugh. Boooooo. 

I think that the issue with the random splitting of albums is not an app issue. I suspect that it is more likely a software change in the devices (players etc.). I’m no expert but if I look at my server that stores all of the albums there are no problems, all albums are complete with all their tracks. It’s only when viewed on a Sonos app that the error appears. It would be interesting to see if someone using a third party app such as SonoPhone or SonoPad is seeing the same issues.

I really can’t see it being an issue with the metadata in the albums, I say that because the error can be random, one minute it’s fine, then a folder rename corrects a previously split album, but then causes a completely unrelated album to split. Also the fact the split albums contain only one track and it’s the same one track in each split. If it was metadata, then the error would be consistent across all albums, I.e. it would always be the same albums affected, but it isn’t.

As I understand it the devices hold information about the library not the app, the app simply reads information from the connected devices. That’s why I believe we should get more excited by a device update than a app update.

That’s just my thoughts, I not a Sonos engineer, it’s just based on some reading about how Sonos works, I stand to be corrected.

Came here to say I have the same problem.

I *really* wanted to play one album in full and so tried changing the tags for the artist, album name and more several times and then updating the library and nothing happened… until randomly it worked. 

Needless to say it is disappointing to find some of my music has vanished in Sonos when I can see it sitting there unchanged in my library and this applies to many albums.

After the failed app update in 2024 this is more frustration.

I understand your frustration. You can still play an album that exhibits the problem. Go to your music library and select Folders, then you can look for your album in its folder there. You will find it all intact, and you will be able to play it. It’s not the best way but it works until hopefully Sonos sort this.

I wouldn’t play around with your metadata. You might make things worse. I hope that helps.

I ran into this exact same issue… I have duplicate entries of certain albums, each duplicate has the same single track.  Other tracks on that album are not accessible in the controller.  Different controllers behave the same.  I did some troubleshooting of my own, rebuilt the problem albums, and those albums showed correctly, but the problem moved to a different set of albums.  I came to the conclusion that this must be a Sonos bug and found this thread.  Hoping that Sonos takes this seriously and comes up with a fix.

3rd Party Apps also have issues with it. I use one called Clic and I’ve been in touch with the developer on some of the mechanics of the App, I’ll ask him where it goes to get Local Music Library data. In the meantime, here’s what I see across Sonos’ Apps, Clic, and Music for macOS:

--Brian

Music Library data is stored on the Sonos speakers, a copy on each one.

Not sure if that data is synchronized as it is indexed or once the device doing the indexing has finished.

There has been past discussion of older, slower devices passing the index-request to a more capable device. Not really sure how that looks from inside the system but as a user I can't see anything.