@heyigun Just so you know, "connection preference/ preferred signal source" applies to both (Deco to other Deco & Deco to clients) How to select a preferred signal source on the Deco App

@JymCaniedo You need to contact that ISP for newer version of the firmware. Updating to "regular" firmware is risky. Yes, regular firmware will have the missing options. @David-TP need help on this

@JymCaniedo Did you buy the X55 from an ISP? Your firmware version looks like a customized one.

@heyigun What does that "Oto" option do?

@JymCaniedo It's under "More" tab> "WiFi access control" If you're referring to access the web UI through PC, go to 192.168.68.1 or tplinkdeco.net What's your hardware version btw?

@DanielBG Oh yeah, I forgot: The "WPA2" option for M4 is WPA2-PSK. No need for changing anything. "Still weird that an update can just break working device in such a way" Is this your first time...