Web interface wi-fi signal button. How do I turn it back on?

it is bij design. if you have turned it off in the webgui. its only possible to turn it back on in the webgui. the button does nothing in this case.

so you will need a wired connection to the Box12 to turn it back on.

Okay, I can accept that turning off Wi-Fi in the web interface and turning it off with the button are not related. It's a little strange, but acceptable.
But the fact that Reset cannot restore the settings with Wi-Fi working is clearly a bug.
I got a working router, broke something with the settings, and I clearly expect Reset to return it to factory settings, not factory settings + some of my settings. 
It turns out to be a rather unfortunate user experience.

I haven’t heard from you again, so I’m assuming don’t need any more assistance. If you have any other question, please let me know! 

1. I resolved this issue even before raising this topic on the forum. In order to raise this topic, I had to learn from my own experience how to enable/disable Wi-Fi on a router.

2. No, I don't have a similar output on my Windows or MacOS laptop. I don't have an adapter either. I had to move my large desktop PC to the hallway near the router to turn on Wi-Fi.
 

I raised this issue to point out a problem in the router's software and so that other users could find this discussion if they made a similar mistake.

P.S. I'm a little surprised by your last comment. So, if I hadn't solved this problem myself, I would have sat without Wi-Fi for 12 days waiting for a response on the forum? Very strange.

I'm glad you were able to fix it with your desktop PC ​@PavelX 

I completely agree with you, that’s it's not good the modem doesn't show a pop up or warning before disabling the wifi. Therefor I forwarded your feedback about this issue to our development team!