Router reboot is valid.  If the router has got is IP addressing in a mess then it could be slow in giving info to the Sonos products and as i found when using extenders the past, Sonos plays music but gives up on providing the artwork.  Embeded artwork seems to be a simpler task to display, I presume as it is delivered as part of the playing file.  The folder.jpg needs to be matched with the file playing and it seems if the network is poor Sonos gives up on this if it exceed a certain response time.  These are my assumptions when I had the same issues. I was using powerplugs at the time, now I have Ethernet connectivity it rarely becomes an issue.

I have given up on managing playlists by the Sonos App, not only because of the Album artwork flaws but also because of the poor playlist management features. Best alternative I found so far was to manage all tracks in the Apple Music App and use the AirPlay2 streaming. Artwork stored in the track metadata are nicely displayed by the Sonos App.

OK, so now I see cover art in the queue on my desktop controller for most of the tracks - but not all. Now playing is empty. The queue is one single imported playlist. (I basically only use imported playlists, as I have a program that makes a random selection of album every day.) There is a folder.jpg in the folder for the playlist; no embedded cover art.

I also had an imported playlist open in the browser - no cover art.

Note that Sonos had been idle for the last six hours or so.

I also noticed that on the embedded ones, the art is kind of slow to turn up, like 15-20 seconds after the upgrade. It used be faster.

I’d still recommend a router re-boot.  If the router has invalid or duplicate ip addresses stored it will slow down your lan and delivery of info to Sonos units.  I found that after a Sonos update especially, as each speaker is restarted as part of the update and the router may no have refreshed the Ip addresses properly.

OK, I give in. I downloaded and installed new firmware for the routers. Cover art for folder.jpg appeared instantly in the Sonos player. Interesting enough, it still takes some time for the cover art to appear with the album that has the cover art embedded.

Thanks for being persistent in leading me in the right direction!

Your final  comment aligns with my existing understanding, which is that the folder.jpg route is quicker to load than art embedded in each file, all otber things being equal. 

Still no music library cover art here. No problems with Amazon’s art.

I did reboot the file server. No change.

Power cycled my Beam (but not Sub or Surrounds.) No change.

Power cycled a single One SL. No change.

Restarted Controller, on Android tablet. No change.

Rebooting all Sonos is a massive PITA as many power cords are buried so I’m skipping that for now.

Spouse is using the network so a router reboot is out for a few hours, I’ll try that tonight.

Diagnostic if that helps anything: 1545282987

It may pay to keep track of the “Associated Product” from About My System. Occasionally, check this player’s network connection for long PING times and dropped packets. If this player is struggling, the artwork fetch might time out.

Rebooting router didn’t get the album art back.

Dropping the music library, re-indexing and re-adding did nothing.

I hope Support can see something in the diagnostic I sent in.

I am in the same boat. Having just purged all embedded artwork from my library (due to its inability to load faster than a particularly arthritic sloth) to replace with a folder.jpg model, I thought I finally had reliable cover art loading. And I did - until the latest update. Now, no matter what I try I get no cover art from local library sources. I’ve done the power cycle, I’ve rebooted the router, I’ve investigated wireless channel interference, yet the only thing that has changed on my setup is the most recent Sonos update. I’ll be following this thread with interest (and general annoyance) to see what feedback is received.

The update from my corner is that while I did get back the cover art after rebooting the router, the effect only lasted for a few hours. Now I’m back on the situation where folder.jpg does not display, while embedded ones do, if with some delay.

I should add that I have fixed IP addresses for all Sonos devices. Only one of them is directly connected to the router, and that is by cable. None is connected by WiFi.

It does indeed sound like we are in the same position, the only difference being I have a Boost wired into the network and not a speaker. Hopefully someone from Sonos will be able to provide some more clarity on the situation 

Yep, same problem here.

folder.jpg not showing on either the Windows desktop controller or the Android app.

Just started very recently.

It took me a while to work out that albums with embedded art versus just a folder.jpg were what was making art visible or not 

Same here: no album covers to be seen on iPhone XS Max (iOS 15.1) and Windows 11 PC (Sonos S2, 13.4).

Diagnostic number: 1139511221

And now, without restarting anything, I suddenly see the cover art again. What I did do was to the music from from one zone to another as I went into that room and then I moved the music back when I was done. Exactly when the cover art started to appear, I don’t know.

It seems quite obvious that Sonos made some changes, but it is not as simple as that they are ignoring folder.jpg, but something more subtle. Maybe threshold for when to display or ignore has changed?

I'm not entirely sure why this has been marked as answered, or why the answer that has been flagged is even helpful.....

Nor am I. I’m also puzzled that someone else than me (since I started the thread) can mark something as the best answer. I guess that Spunk accidently pressed the wrong button. Since the issue is by no means resolved, is there any chance that you can revert your action?

I've asked the moderators to remove this Best Answer.

No, it wasn’t me. And I would be very surprised if someone other than the thread starter or a moderator could do that.

Same issue here! The artwork loads intermittently in the queue but never in the now playing screen.

Tried different wireless channels and a router reboot but no luck.

Is there any benefit in submitting a diagnostic?

Yes, a diagnostic and follow-up with support creates an ‘incident’. Corporations track incidents and respond by allocating resources to reduce support costs. Plus, the additional diagnostic contributes to a wider variety of cases to study.

But is there any point with sending diagnostics alone? The problem I have with calling support is the time it takes. Here in Sweden there is typical a waiting time of ten minutes or more, and it is only available 10-18, and that’s when I’m at work. Yes, I work from home, but still I’m at work, and I can’t bill my client for talking to Sonos.

Send the diagnostics and post the number here, Support will usually find the issue and respond. If we haven’t seen anything back by Monday we can request that Support staff look at the topic.

I just realized I have an un-updated controller on the Windows box I use for updating the Honda, firing it up now to see what it looks like there. And on Windows the 13.3 controller shows no artwork from the Music Library.

I doubt it is a delay issue here, I have my setup on SonosNet with 2 Wired Beams and a wired Arc. Channel utilization is 20-25% according to my RF monitor. This setup has not changed for many months now.

I have tried both a SonosNet connected Beam as well as an Ethernet wired Beam, both show the same symptoms. The Wired Beam and controllers are all on the same Gigabit switch.

Checking my Linux (non-Sonos) controller shows no artwork on the Music Library either, since it connects to the player directly it points to being a firmware issue on the speakers, not a controller bug.

Running this on a Raspberry Pi: https://github.com/pascalopitz/unoffical-sonos-controller-for-linux

Well, I've submitted diagnostics. Ref 1229186748, if anyone from Sonos is floating around 

Yeah, just like I did 20 hrs ago. Heard nothing back. Apparently no Sonos employee floating around.