Speakers controllable via web app (and others) but not Official iOS or Desktop Sonos App

Hey everyone,

I dont even know where to start so I’m just going to list the problem(s) I have, my network and system topology, any troubleshooting steps I’ve taken, and I’m hopeful someone can help. Or tell me it’s not just me.

The problem + initial info:

1. Specifically home theater setups (Family room: Arc+Play:1s+Sub (Gen1)) and Basement TV: Beam+Play:1s+SubMini) will show in the iOS app but will not be controllable.
2. Expanding a bit:
   1. I cannot play music, change settings, enable night or speech enhancement modes, change volume, group, or otherwise do anything with the ‘room’ in the iOS app. The device is usually missing from the desktop macOS app.
   2. The speaker is fully controllable via Spotify, AirPlay2, the Sonos Web App, Home Assistant Sonos integration, and connected voice assistants.
   3. Sometimes the Desktop App will see the speaker and will be able to control the speaker but not the iOS app.
   4. The speaker is connected to my home network and to the same access point as other speakers in my system not experiencing this issue.
   5. Currently Basement TV HT is working fine.

My network:

1. Unifi network with 4 APs, all connected to the same main switch. Speakers are connected to various APs and all but the home theater setups work 99% of the time. Family Room and Basement HT setups frequently experience the problem mentioned above.
2. My gateway is a UDP-Pro that is upstream from the main switch. 
3. All APs are broadcasting on 40mhz channel width for 2.4 and 5ghz.
4. As mentioned before, speakers are connected to various access points and are controllable and group-able with each other. This is true even if my phone is connected to a different AP than a speaker (which is, i’m sure I dont have to say, how a mesh network should behave)

My Sonos system:

1. 15 rooms, of that:
   1. 2 home theater setups, wireless (which is annoying I can’t hardwire the soundbar and disable SonosNet, but keep the ad-hoc 5ghz network for surrounds and sub, but I digress.)
   2. 2 hardwired amps (gen2), wifi disabled
   3. 1 hardwired play:1, wifi disabled
   4. Everything else is a single speaker and wireless. No stereo pairs.
   5. Because it will be picked apart: the hardwired play:1 and Amps were never an issue before the Spring 2024 “update” 🙃. They are also 100% reliable. They’re alsooOOoOoOo not broadcasting a SonosNet network, so I doubt there’s a loop issue here.
2. I want to reiterate that it’s only the HT setups that experience this problem. The single speaker setups (wired or wireless) are usually almost always fine.
3. All speakers are on 82.3-60160

Troubleshooting:

1. All speakers, including the rears and subs of HT setups, have an assigned IP address. This helped with the sub and rear disconnects after a restart or update. (Rears and sub were assigned an IP during initial setup, if you’re curious).
2. Rebooting router, switch, APs, soundbar, rear + subs, in that order (oftentimes this just results in my subs and rears being orphaned for a while until they reconnect to the soundbar, ugh). 
3. Reinstalling the Sonos App sometimes gets the speaker become controllable. Rare. Hasn't helped lately (why i’m reaching out now)
4. Restarting my phone, iPad, MacBook.
5. resetting network settings in iOS.
6. When I was desperate a couple weeks ago, I factory reset my whole basement HT setup. This didn't help (it still started experiencing the problem a day or so later). But what was strange about this is:
   1. Originally the room was called Basement TV, when I factory reset it, I named the room “Basement.” After a few hours the room changed its name back to “Basement TV” :/ 

Update, during the course of this writing: Family Room came back to a controllable state briefly. Was stuck displaying TV input, rebooted the app, and now it says “no content” in the iOS app. Other apps shows TV input, as expected. Please put me out of my misery. 

Hoping there’s a fix that I’m missing.