Frequent, short disconnects/drops
I have 3 Deco X55s in my house. The primary one is attached directly to my cable modem upstairs (the modem is just a modem -- it has no router capabilities). The other two are connected to the main router via wired backhaul. I have 2 SSIDs, one main (5 GHz/2.4 GHz) and one as the Guest Network for my IoT devices (2.4 GHz only).
Throughout the day, I'm getting random disconnects. Usually these drops are very short -- typically no more than a second -- but it's enough of a disruption to cause downloads to fail, end video calls, etc. Currently I have 2 machines running 24/7; one is my personal desktop (connected to the main router over 5 GHz), and the other is a HTPC in the living room (connected to one of the backhauled Decos over Cat5). These 2 machines are running PingInfoView, hitting both the main Deco's IP and Google's DNS (8.8.8.8) once per second, so I can get a picture of network health (internal vs. external, wired vs. wireless). In the last hour, my desktop has logged 8 times where it couldn't reach the Deco and 7 times where it couldn't reach Google's DNS. The HTPC unfortunately was not running PingInfoView because it was reset after a system update, so I can't compare this most recent spurt of errors, but in general it records few if any drops. This leads me to believe that there is an issue specifically with the wireless.
Fast Roaming and Beamforming are both disabled. I switched the 5 GHz band back down to 80 MHz channel width to see if that would improve stability as well. QoS is not enabled. My wife's work laptop usually connects over 2.4 GHz and she reports network issues as often as I notice them.
I have attached logs from the router. The recent failed pings occurred around 16:27:51, 16:27:59, and 16:28:04, so the logs start right around when these issues cropped up. Happy to provide any additional information as needed. Thanks in advance.