@mryan143 if you can I would suggest you to try another switch, best to grab a cheap Tplink unmanaged switch on amazon and return if it doesn't fix. Here's a similar discussed topic: https://community.tp-link.com/us/home/forum/topic/633502?

  @Espress0-0 

Thanks for the suggestion. Unfortunately, I've already tried exactly that -- an unmanaged TP-Link switch -- and the problem persists. 

My issue is *both* wired *and* wireless devices are routinely disconnecting and reconnecting.  And it turns out it's more than the ones I listed.  My Fire TV cube is doing the same thing - I just wasn't previously aware because it isn't used that much and I had not set up a connection alert for it.  

  @Riley_S 

Thanks for the reply.

To address/clarify a few things:

(1) Sonos is functioning perfectly.  I am, of course, using "SonosNet" to network those speakers, as suggested by TP-Link support.

(2) Wireless devices are having at least as many disconnects/reconnects as the hard-wired clients.  Given that it is both wired and wireless clients that are unstable, it would seem many of the possible explanations are off the table (e.g., the switch, ethernet cables, wireless signal, etc.). I've also controlled for the variable of the ethernet port on the Deco, both by using different ports, and even using a completely different Deco hub to serve as the main router.  Nothing has fixed the problem.  

(3) There is no pattern or trend that I can identify.  Even the clients that offend the most tend to be inconsistent. For instance, the Smart TV mentioned previously seems to be fairly stable now, but the Fire TV Cube (wireless) and my other Shield device (wireless) are the ones most frequently disconnecting/reconnecting, along with the Synology NAS (hard-wired)  Tomorrow it may be the main Shield device again and the Smart TV.  

The past few days it appears that I may go several hours with few issues and then I start getting numerous disconnects/reconnects in a fairly short period of time. I can't even identify a trend in when the connections are the least stable.  Sometimes it's during the day, other times in the evening (when there tends to be increased network traffic), and other times -- like last night -- I'm getting the bulk of the alerts between 1 and 5 a.m.  

I am going to PM you to send a more up-to-date and comprehensive log for your people to review.  Unfortunately, I am getting really close to the deadline to return these, and I simply can't justify keeping them with a network this unstable.  I had none of these issues with my previous Google Wifi/Nest set up. 

  @mryan143 Sorry, I totally missed that comment of you. You seem to do a lot for troubleshooting already. At this point, my advice is to return the Deco mesh if you're still able to, or file a claim to replace the units with Tplink. Another thing though, I notice that my Samsung TV goes offline a lot with being wired/wireless every single time I turn off the TV, it will go offline. But when I turn on the TV for example, the connection being established but it happens too fast so I don't normally notice it. Not sure if that's the case with your TV, when you're watching TV, the connection dropped or it only shows as offline in Deco when you turn off the TV? I don't have any Android devices but I always see a bunch of 'phone' devices going online and offline in my logs. Since my network still works so I don't bother checking out what are those devices anymore. Tbh, I have been using the Deco mesh for a couple months now, it has improved a lot in terms of coverage and speed for me, but in terms of stability, it still needs more work than my previous setup. I hoped for a set and forget system when I purchased the Deco mesh but it's not obviously. Have passed my return window so I'm kinda stuck with this and try my best to keep it running without satellite units dropping out of nowhere. Honestly I feel that I get what I paid for.

  @Espress0-0 

Thanks for all your replies. I had the same thought about the TV, but unfortunately I lose connection constantly while it's on and being watched. And it's not just the smart TV I referenced earlier -- it's also the one in my kids' room. Honestly, I have at least 8-10 devices that repeatedly disconnect/reconnect throughout the day and it does not matter if they are hard-wired or wireless. They include two TVs (maybe more, but I never even got around to connecting my other smart TVs), two NVIDIA Shields, a Fire TV Cube, a Ring doorbell, two different Synology NAS's (hard-wired), and XBox One X and a couple of others.  And those are just the ones I bothered to set connection alerts for. I suspect this problem is far more widespread than TP-Link lets on and/or than many users are aware, if only because people aren't setting connection alerts for known devices one-by-one the way I did.  And the only thing that prompted me to do that was getting constant pop-ups on my smart TV that there was no internet.  

All imaginable troubleshooting has been tried (static IPs, turning off Fast Roaming and Beamforming, assigning them to connect to a specific hub, changing the hub serving as the main router, confirming ISP modem in bridge mode, changing the switch, removing my security camera system, removing Sonos, making sure Sonos was using SonosNet, etc.).  

You simply wouldn't believe me if I showed you the full extent of the problems. It is like nothing I have ever seen. 

I tried really, really hard to like this system but the situation is simply untenable.  I returned all FIVE of my XE75 hubs today, and I'm not sure I've ever felt more relief returning a purchase.  

  @mryan143 Sorry it didn't work out for you. I went through a set of Deco mesh previously with so many issues and I ended up exchanging to my current set. I feel you, I spent a lot of time reading logs and tried to catch the culprits. I cannot remember how many times I reset the network, swapped out devices, troubleshooting myself and got mad by my family for the unstable network :D. I feel that I now have more understanding about how Deco works, they don't like any other non-tplink devices or any extra settings beside the original settings, no DHCP reservation, no port fwd, any slight changes will freak out the network so I'm trying to lay really really low for this. Anyways, best wishes on your next setup, (check out the Dongknows page for network devices reviews).