@Paul_R13 

So I am running the Deco BE16000 system with TP-Link EP25 wall switches and Eufy C120 cameras.  These are all integrated into HomeKit.  Everything seemed to be working smoothly until I switched my Deco system from Router mode to AP mode.  

After making the switch and rebooting all devices, connection to the 2.4 GHz devices were spotty. From within HomeKit the wall switches would often show up as not responding (even though they seemed to consistently repond to on/off commands though with some delay).  My wifi cameras would either disappear or take a long time to pull up a live stream.

All of the connections seemed to be strong - but there was a lot of lag and some of these devices would just randomly go MIA.  I ended up enabling the 2.4 GHz IOT network, resetting all of the devices and forced them all to join the IOT Network.  Well after doing that everything now is lightning fast and consistent.  I have had no issues since.

I'm not quite sure why this seemed to fix the issue.  I did notice that when setting up some of the 2.4 GHz devices, I would sometimes have to try to set them up mutliple times in order for them to get the 2.4 GHz network, while when using the IOT 2.4 GHz network, they seemed to be able to connect without needing multiple attempts.  Perhaps on a shared SSID this was causing an issue, while using the dedicated 2.4 GHz network the devices had a more reliable connection if they went to sleep or needed to reconnect - I'm just not sure.  When operating in Router mode instead of AP mode, none of this seemed to be an issue for some reason.

So maybe give the dedicated 2.4 GHz IOT network a shot and see if that resolves some issues?

Good luck.

  Thanks @Mike101 .

I intially put all of my wifi cameras on the Deco IoT network and they connected immediately with a strong signal. Then, gradually, the cameras just mysteriously drop out.

I'm going back to my Netgear Nighthawk router so I can have some stabilty. I'll use the Decos as Access Points only -- or just return them. I have young puppies to monitor, so I just don't have time to trobleshoot this Deco mesh network. I suspect the Decos don't fully comply with the IEEE 802.11 standards, otherwise this would have been a simple transition...