I have 3 Deco M5 units running in Router mode with wired backhaul. The main Deco is connected to my ISP router, which has WiFi disabled. I've had this setup for many years and everything has worked fine - all devices connect to the Decos which takes care of DHCP, etc. The main Deco is the only device that the ISP router sees.

However, this morning something strange happened. After the ISP router restarted due to maintenance, devices connected to the Decos intermittently lost connectivity. When I logged into the ISP router's web interface, I saw some devices from my (Deco) wireless network show up in the router's connected devices list. The devices definitely weren't connected directly to the ISP router (because WiFi is disabled), so must have showed up there because the Deco somehow reverted to access point mode. I don't have the logs to verify this, but I think it can be the only explanation.

Has anyone else seen this before - Deco M5 randomly reverting to access point mode? I've restarted the Decos and upgraded the firmware and things are working fine for now, but wanted to check if this is a known issue.

Thank you!