Any updates on this one? I’m using 1.5.1 Build 20201022 Rel 66804. Still seems to be a problem in Mar 2021. Up until today, I’ve been using 3 Decos in an AP mode without a problem. As soon as i installed a 4th Deco in star-configuration (Router>Deco>Switch>Decos) and switched to Router-mode, my devices stopped seeing the wired ethernet connection.
Update: Troubleshooting my device/PC fixed Gateway connection issues. Now, my device is seeing ethernet again. I’ll report back if this problem returns after power disruptions.