@glitch: Thank you for your input. How can i disable it? Where?

You mean, for a user it is better to loose the connection instead of getting a popup? it accidently happen to me twice. Smartphones and fingers are are not very precise. My other router warn.

i wrote, a popup maybe “you try to disable wifi, although you are connected via wifi. Are you shure, that you can access your device via LAN?” or better not to allow disabling, when not connected via LAN.