Just upgraded my router to a TP-AEX5400 and ran into this issue.   From what I gather still no update on a fix.  Just chiming in to follow and see about solutions either being updates or workarounds.

If sonos just allowed legacy smb connections as well as more recent ones then it would work with the older routers like it used to.

We are still waiting to have this fixed.  Sonos doesn’t recognized the USB drive attached to my TP-Link router?  Any time line when this will be addressed?

I am having the same exact issue with my TP-Link Deco mesh router. 

I spoke with Sonos Tech Support about it, and of course they acted like they never heard of this before, yet I see some of you have been encountering this for months.

I’d like this addressed, as the router has the USB port set to share and Sonos sees the library in the USB port and has the login credentials saves. Not sure why Indexing the library is an issue.

Does the TP-Link router treat connected USB drives as NAS devices? I.e does it have the necessary software to run SMB? Not all routers have built in NAS firmware to use USB connected drives as an NAS.  Also, remember that Sonos S1 uses SMB v1, but S2 can use SMB v2 or above.

The Sonos speaker (Linux) is running the library index, by connecting to the NAS via SMB, and not the Sonos controller on your device. 

However, if it shows up as a shared drive, and not an NAS, it’s handled differently by Sonos. 

I am not sure. All I know is the TP-Link router allows you to use the USB port as a network share with a USB 3.0 port to attach a flash drive, SSD or hard drive.

Very convenient to share media. But after the initial media index, it won’t index it again and says it’s “not available”

It is hard to place blame on either TP-Link or Sonos without this knowledge. The use of a USB device, whatever version, suggests (but not certain) not an NAS drive, which begs the question, if your TP-Link is allowing access from other devices to a network share. This information should be in the TP-Link manual. 

Which version of the Sonos OS are you currently running? Have you set the share on this USB folder to all devices? Is there any VPN, port blocking, or other virus protection running anywhere? What device and OS is your controller running on?

I am running the latest, Sonos 16.0. on a PC with Windows 11 Pro and on and iPad Pro with iPadOS 17.3.1

I have the USB set in the TP-Link Deco router as Access Authentication with username & password, which was entered in the Sonos app when it first read the drive.

Sharing on Windows looks normal?:

We’re reaching the limits of my comfort level, to be honest, especially as my preferred OS is MacOS. 

As a test, if you copy a handful of songs to your C: drive, does Sonos work with them?

Yes. The same songs are on my computer in various folders. When I’ve indexed them in the past, it always worked and self-indexed daily.

Now with this new router with a USB share, I bought it purposely for that. To share my music across the network with the Sonos app. Getting the Music Library set in Sonos is not the issue, it’s trying to Index them again under “Library Update” or “Update Music Library Now” doesn’t work. Says that shared USB drive isn’t available, yet it is still in my list under Music Library | Path and in the Music Source list in the app.

I am seeing that this has been going on for months with others. Why doesn’t Sonos create an Index file within the app, a database…………….and NOT write to the USB drive, if that’s the issue?