@drogue THIS HAS WORKED FOR ME ALL DAY SO DAR WITHOUT DROPPING A CONNECTED DEVICE.
I had the same problem..
with Deco XE75 / XE75 PR0
I REFORMATTED OR RESET THE DECO DEVICE AND RE-DID THE FULL SETUP..
>>> I ENTERED MY OLD SSID AND PASSWORDS <<< FROM MY ORIGINAL ROUTER.
FOR THE MAIN NETWORK
I USED MY 5G SSID & PASSWORD.
I WENT BACK INTO THE APP AND CREATED A GUEST NETWORK
SET THAT ONE UP AS 2.4 ONLY
>> WITH MY SSID AND PASSWORD FROM MY OLD ROUTER <<
I SET MY MAIN NETWORK IS 5G ONLY DOING THE SAME
AND RE-CONNECTED ALL MY DEVICES INDIVIDUALLY
I ( DID NOT DISABLE ) BEAMFORMING
I HAVE NOT HAD ANY ISSUES WITH DISCONNECTING AND CONNECTING CLIENTS