I am using Deco M4 (2 packs). 1st main Deco is at the first floor connected wired to the modem, 2nd Deco unit is connected wired from the 1st Deco unit at the ground floor. 

I am experiencing intermittent connection loss with my phone. The WiFi disconnected my phone then my phone connects back to the wifi automatically. It also happen to most of the mobile device in the house. I noticed this issue happened since I got the Deco M4. Did not have this issue with my previous router. It disconnects the most while I'm watching video like youtube, netflix.

When my phone wifi is disconnected, LED status is white. Both deco is online.

Currently I do not have this issue with my laptop. While playing game or doing any work on the laptop, I do not notice any connectivity losses.

I've tried to restart and reboot the router, disconnect the 2nd Deco and use only the one Deco, disable beamforming, disable fast roaming, swapping both deco units. Issue is still occuring. I've updated to the latest firmware.

Would appreciate if you could give me any insight to this issue.