@TP-Link 

Hi team, thanks for your quick reply.

Would any Deco blink red when the connection dropped?

Nope, green all the time on the devices and also on the app.

How about the dropping frequency of mobile devices?

The same, it's random. But to clarify, all devices says they're connected to the wireless network but can't communicate.

It's really weird, but I'll share something that happened the other day: I've a smart lamp in the kitchen, connected to the Kitchen Deco (which is connected via WiFi to the main Deco in the living room). My home assistant (installed on a PC connected to main Deco via WiFi) shows the device is unavailable and can't even ping the sonoff device's IP address - but I can ping and access the smart lamp's web server from the Mac connected to the Master Bedroom Deco (which is also connected to the main Deco via WiFi). On the Home Assistant PC I see the MAC address from the lamp is not recognized, and even trying to set that info manually doesn't work. I don't need to restart the PC or turn the smart lamp off/on, if I only restart the Decos all become functional again.

That might sound like a problem on my PC, but as I said it is only an example. The other day my Mac was the chosen one - connected to the network but couldn't ping other devices within my LAN and, that time, neither access any website on the internet.

What are those IoT devices and can I get their models?

I have several Sonoffs in the house (mini, D1 and basic R3), some flashed with Tasmota (9.2.1 and 9.3.0) and others running the stock firmware, but as shared before, this is not happening only to these devices - it's just where I feel the most impact (I can easily switch my Mac to a 4G connection from my cell phone when this happens, but not the same applies to IoT devices)

And may I also know the model number and operating system of your smartphone?

Sure, I'm using an iPhone 8 with iOS 14.4.2

If possible, please send me the system log on the web UI http://tplinkdeco.net when the connection dropped again before restarting the Deco;

I'll certainly do, I rebooted the entire system yesterday so I'll send you as soon as I face the issue again, ok?

Thank you.

@TP-Link 

Please find attached my logfile. It took a few more days for this to happen, but let me explain what's happening right now:

1-) From my Home Assistant PC (IP192.168.68.116 connected to the main Deco living_room) I can't reach my light (IP192.168.68.126 connected to kitchen Deco)

2-) From my Mac (IP192.168.68.100 connected to master_room Deco) I can ping and do everything with my light

3-) from my Mac I can also talk to the Home Assistant PC

4-) And it doesn't matter what I do on the Home Assistant PC, this only gets fixed when I restart all 3 Decos

I'm sending another message with the "ping tests" attached.

Ping tests printscreen and log the logs from the light

00:00:00.050 CFG: Loaded from flash at F8, Count 692
00:00:00.055 QPC: Count 1
00:00:00.062 Project tasmota Luz Nicho Cozinha Version 9.3.1(tasmota)-2_7_4_9(2021-03-09T16:12:28)
00:00:00.550 WIF: Connecting to AP1 uairilis Channel 7 BSSId E4:C3:2A:F0:16:7E in mode 11n as tasmota_1ACF3D-3901...
00:00:03.753 WIF: Connected
00:00:04.007 HTP: Web server active on tasmota_1ACF3D-3901 with IP address 192.168.68.126
00:08:52.260 MQT: Attempting connection...
00:08:52.473 MQT: Connect failed to 192.168.68.116:1883, rc -2. Retry in 10 sec
00:08:53.483 QPC: Reset
00:09:03.258 MQT: Attempting connection...
00:09:03.469 MQT: Connect failed to 192.168.68.116:1883, rc -2. Retry in 20 sec
00:09:24.298 MQT: Attempting connection...
00:09:24.512 MQT: Connect failed to 192.168.68.116:1883, rc -2. Retry in 30 sec
00:09:55.278 MQT: Attempting connection...
00:09:55.491 MQT: Connect failed to 192.168.68.116:1883, rc -2. Retry in 40 sec

This time I used the network optimization utility to try to recover the network, but my experience with this is that in a couple of hours I'll have other issues and I'll finally reboot the entire system.