Airport Express in Mesh Network

Apple released a patch not long ago for all the AirPort base stations which effectively Gave all of them Airplay2 support.

Unfortunately, this is not correct. The A1084 and A1264 versions of the AirPort Express do not support AirPlay 2, although they will work with the earlier AirPlay.

Please refer to the Apple support document below for more details.

https://support.apple.com/en-us/HT208728#airplay

Devices you can stream to

• Apple TV 4K or Apple TV HD with tvOS 11.4 or later
• HomePod with iOS 11.4 or later
• Speakers connected to the Audio Out port on AirPort Express 802.11n (2nd Generation) with the latest firmware update
• AirPlay 2-compatible smart TVs2 with the label "Works with Apple AirPlay"

As far as price, my A1392s were about $20 each. You should be able to find the A1264 for $10 or less. The 2nd Gen A1392 is supported by Apple until April 2025, but I would not look for any future updates on any of the Express models.

(the TP-Link Deco m5), I believe it's an N network, not quite AC yet.

Definitely AC wireless.. but that does not mean the two units are connecting over AC.. which it is designed to do.. the connection could be over 2.4ghz.. and much much slower. To find out how well your connection is working perhaps do a few network speed tests via the upstairs node.. preferably using ethernet from computer to the node.. but wireless is ok if nothing else is possible.

Question:

Why does the music on the first floor break every now & then like there was a disconnection momentarily. This occurs randomly and only to the Airport Express A1084 (802.11/g) but not the A1264 (802.11n). Could it be a speed issue, that the 802.11/g is having difficulty in keeping up with the N network?

As I understand your situation.. It cannot have anything whatsoever to do with G wireless connecting to N wireless.. since

another Airport Express A1084 (802.11/g) hardwired to one of the Deco Units

And a hardwired unit has no wireless working at all.

Figuring out a cause may be problematic.. you will immediately perceive the main issue is the A1084 is no longer supported.. and even the airport utility v6 (Introduced at Lion OS) cannot find it. Apple ceased support long long ago. You need to use PC with v5 airport utility.

Have you tried the obvious one of switching the two express so A1084 (13+ years old) is connected to the main router M5 and the A1264 (10+ years old) to the node.

If it fails in this setup throw the A1084 in the bin and buy another ancient A1264.. or even perhaps blow the budget on a Gen2 express which could be up to 9 years old. A1392. (They tend to be rather overpriced though).

There can be lots of things going on.. but hard to figure out with such old hardware. A1264 can be purchased for just a few dollars on eBay and is well worth it just to have a method of testing.

Keeping Airport Utility v5 open and seeing if the A1084 keeps dropping off the network might also give some clues.

Neither the A1264 nor the A1084 officially support AirPlay 2......the current standard.......so that might enter into the issue as well.

It is remarkable that the A1084 will even still power up at all. It's at least 13 years old as much as 17 depending on when it was placed into service. The tiny copper contacts inside the Ethernet port on the Express tend to get corroded with age, as well as the tiny copper contacts on the Ethernet cable plug. Use a tiny flat blade screwdriver to very lightly scrape the copper strips to try to improve the quality of the electrical contact between the Express and the Ethernet plug. No guarantees that this will help, but it cannot hurt.

It's your call, but an A1392 version of the Express might be a better choice if the budget permits. This model runs much cooler than the A1264, so it will have a better chance at a long life. The model also supports AirPlay 2, so you will be up to date with AirPlay.