Deco XE5300 (3x XE75) Wifi6E mesh system was working great until last week it suddenly dropped all of my smart devices. 
 

When I set up my new Deco mesh system I was able to connect all my smart switched connected (TP-Link Kasa Switches and Dimmers, Pura Diffusers, Ecobee3 and Ecobee4 thermostats, Ring Pro Chimes, Feit Electric 3-way Dimmers). 
 

I was able to set schedules with all the TP-Link Kasa switches and control them through the  Deco app. 
 

Randomly (no changes to firmware, settings or anything), all my smart devices dropped off the network, and I cannot add them back to my network. I factory reset the smart devices and sim cannot add them back. 

I have Beamforming and Fast Roaming off.

I even have Wifi6 as dedicated backhaul only.

I do have a small amount of smart devices working, but it's because they connect to or act as their own hub (Amazon Echos, Ring Hub, Ring Pro Doorbell, Ring Floodlights). 

I have been struggling for the past week trying to get my smart devices reconnected with no success. Please help!!