Previously I was running an AX11000 which was broadcasting 5ghz only and 3 m5 deco units that were broadcasting 2.4ghz (AP mode). 
I still had some dead zones, especially for the 5ghz signal, so I figured to try adding xe75pro to the network to replace the ax11000 5ghz. 

I want a seperate network as my IOT devices are all setup to connect to a different SSID than my main devices. So I configured the IOT network, and setup the main network for my other devices. Setup took much longer than expected but finally it completed and I updated the decos. Devices began dropping constantly like flies. I tried every setting I could think of, but the issue persists. When its connected, the connection is strong and stable (800 on 5ghz and 60 on 2.4ghz) - however maintaining this connection seems to be an issue as the devices keep continously dropping. They will connect back again after a few seconds, sometimes a few minutes. 

I've disabled mesh for all my fixed devices. I disabled beamforming and other similar settings. I also set address reservation on the router for all decos. Network optimization ran as well. 

I'm at a loss and it looks like this guy will be going back if I can't figure this out