Orbi 770 and IoT

Hi there, 

I recently purchased an Orbi 700 with 3 satellites. Wifi is fine everywhere in my house (3 floors)

I have set up an IoT network to connect my Meross plugs and smoke detectors. Meross devices only accept 2.4ghz wifi network so I have limited the IoT network to 2.4ghz with a different ssid name ("Domotique") and password than the main wifi network.

Everything is fine on the orbi app, but IoT network does not appear on my iPhone and iPad. I have only seen the IoT network once but it was impossible to connect...

Any idea why? I am a bit lost

One last question: I have another WIFI network named NTGRBH_28940... what is that network and who to connect?

Thanks for your help! 😉